Scholars@Duke
Adrienne Stiff-Roberts

Adrienne Stiff-Roberts

Professor of Electrical and Computer Engineering
Electrical and Computer Engineering
adrienne.stiffroberts@duke.edu
Box 90291, Durham, NC 27708-0291
3511 CIEMAS, Durham, NC 27708

Selected Publications

Correlation of Emulsion Chemistry, Film Morphology, and Device Performance in Polyfluorene LEDs Deposited by RIR-MAPLE.

Journal Article ACS applied materials & interfaces · April 2023 Thin films of polyfluorene (PFO) were deposited using emulsion-based resonant infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE). Here, it is shown that properly selected surfactant chemistry in the emulsion can increase crystalline β phase (β- ... Full text Cite

Effect of solvent on the emulsion and morphology of polyfluorene films: all-atom molecular dynamics approach.

Journal Article Soft matter · March 2023 The morphology of conjugated polymer thin films deposited by the resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) process is related to the emulsion characteristics. However, a fundamental understanding of how and why the emulsion cha ... Full text Cite

Influence of Annealing and Composition on the Crystal Structure of Mixed-Halide, Ruddlesden-Popper Perovskites

Journal Article Chemistry of Materials · April 12, 2022 Mixed-halide two-dimensional (2D) hybrid organic-inorganic perovskites offer an important opportunity to control the band gap for applications in optoelectronic devices. This study focuses on phenethylammonium lead halide [(PEA)2Pb(I1-xBrx)4] films, the pu ... Full text Cite

Phenomenological mechanisms of hybrid organic-inorganic perovskite thin film deposition by RIR-MAPLE

Journal Article Journal of Applied Physics · September 14, 2020 Resonant infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a promising technique for the physical vapor deposition of hybrid organic-inorganic perovskites. The approach already has been used to deposit both three-dimensional and two-dimensi ... Full text Cite

Transparent mxene-polymer supercapacitive film deposited using rir-maple

Journal Article Crystals · March 1, 2020 In this work, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE), a novel deposition technique, was used to produce a transparent composite electrode of polyflourene (PFO) and two-dimensional (2D) Ti3C2Tx nanosheets, which are part of t ... Full text Cite

Tunable internal quantum well alignment in rationally designed oligomer-based perovskite films deposited by resonant infrared matrix-assisted pulsed laser evaporation

Journal Article Materials Horizons · October 1, 2019 Hybrid perovskites incorporating conjugated organic cations enable unusual charge carrier interactions among organic and inorganic structural components, but are difficult to prepare as films due to disparate component chemical/physical characteristics (e. ... Full text Cite

Deposition of β-Polyfluorene by Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Journal Article Journal of Electronic Materials · May 1, 2019 Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit thin films of polyfluorene (PFO) with semicrystalline phase domains (β-PFO), which has been performed, previously, only by solution phase processing. ... Full text Cite

Two-dimensional hybrid organic-inorganic semiconductors deposited by resonant infrared, matrix-assisted pulsed laser evaporation

Conference Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2019 Hybrid organic-inorganic semiconductors, such as hybrid perovskites, are crystalline materials with unique properties derived from the organic or inorganic components. Resonant infrared matrix-assisted pulsed laser evaporation (RIRMAPLE) is a gentle physic ... Full text Cite

MAPbI3 Solar Cells with Absorber Deposited by Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Journal Article ACS Energy Letters · February 9, 2018 Resonant infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a gentle thin-film deposition technique that combines the facile chemical control of solution processing with the growth control of vapor-phase deposition, yet one that has not been ... Full text Cite

Deposition of Methylammonium Lead Triiodide by Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Journal Article Journal of Electronic Materials · February 1, 2018 Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit the metal-halide perovskite (MHP) CH3NH3PbI3 (methylammonium lead triiodide, or MAPbI), creating phase-pure films. Given the moisture sensitivity of these crystallin ... Full text Cite

Resonant infrared matrix-assisted pulsed laser evaporation of hybrid perovskites

Conference Optics InfoBase Conference Papers · January 1, 2018 Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit the metal-halide perovskite (MHP), CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf>, and solar cell performance was demonstrated, thereby establis ... Full text Cite

UV- and RIR-MAPLE: Fundamentals and applications

Chapter · January 1, 2018 Laser beams are powerful tools for diagnostic purposes and growth of thin films. However, the interaction of lasers with organic or biological materials may result in laser-induced photo-chemical and photo-thermal damage to the materials of interest. In or ... Full text Cite

Organic/hybrid thin films deposited by matrix-assisted pulsed laser evaporation (MAPLE)

Journal Article Applied Physics Reviews · December 1, 2017 Some of the most exciting materials research in the 21st century attempts to resolve the challenge of simulating, synthesizing, and characterizing new materials with unique properties designed from first principles. Achievements in such development for org ... Full text Cite

RIR-MAPLE deposition of plasmonic silver nanoparticles

Journal Article Applied Physics A: Materials Science and Processing · September 1, 2016 Nanoparticles are being explored in many different applications due to the unique properties offered by quantum effects. To broaden the scope of these applications, the deposition of nanoparticles onto substrates in a simple and controlled way is highly de ... Full text Open Access Cite

Emulsion-Based RIR-MAPLE Deposition of Conjugated Polymers: Primary Solvent Effect and Its Implications on Organic Solar Cell Performance.

Journal Article ACS applied materials & interfaces · August 2016 Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been demonstrated as an alternative technique to deposit conjugated polymer films for photovoltaic applications; yet, a fundamental understanding of how the emulsion ... Full text Open Access Cite

Hybrid nanocomposite thin films deposited by emulsion-based resonant infrared matrix-assisted pulsed laser evaporation for photovoltaic applications

Journal Article Organic Electronics · July 1, 2015 Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit CdSe nanoparticle films and hybrid nanocomposite films comprising colloidal CdSe nanoparticles embedded in a low band gap polymer, poly[2,6-(4,4-bis- ... Full text Cite

Antimicrobial and bacteria-releasing multifunctional surfaces: oligo (p-phenylene-ethynylene)/poly (N-isopropylacrylamide) films deposited by RIR-MAPLE.

Journal Article Colloids and surfaces. B, Biointerfaces · February 2015 Antimicrobial oligo (p-phenylene-ethynylene) (OPE) films have previously been demonstrated to show effective ultraviolet A (UVA) light-induced biocidal activity; however, a serious problem arises from the accumulation of dead bacteria and debris on the fil ... Full text Cite

Material properties and applications of blended organic thin films with nanoscale domains deposited by RIR-MAPLE

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2015 Resonant-infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit blended, organic thin-films with nanoscale domain sizes of constituent polymers, small molecules, or colloidal nanoparticles. In the emulsion-based RIR-MAPLE p ... Full text Cite

Organic semiconductor thin films deposited by resonant infrared matrix-assisted pulsed laser evaporation: A fundamental study of the emulsion target

Journal Article Materials Research Society Symposium Proceedings · January 1, 2015 Poly (3-hexylthiophene) (P3HT) thin films were deposited using emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) from emulsions containing different solvents and different alcohols, to investigate the impact of emulsion ... Full text Cite

RIR-MAPLE deposition of multifunctional films combining biocidal and fouling release properties.

Journal Article Journal of materials chemistry. B · July 2014 Multifunctional films with both antimicrobial activity and fouling-release ability based on a biocidal quaternary ammonium salt (QAS) and thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm) were deposited on substrates using resonant infrared, matrix-a ... Full text Cite

Bulk heterojunction PCPDTBT:PC71BM organic solar cells deposited by emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation

Journal Article Applied Physics Letters · June 2, 2014 Organic solar cells based on poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) were fabricated by emulsion-based, resonant in ... Full text Cite

Antimicrobial oligo(p-phenylene-ethynylene) film deposited by resonant infrared matrix-assisted pulsed laser evaporation.

Journal Article Colloids and surfaces. B, Biointerfaces · April 2014 The antimicrobial oligomer, oligo(p-phenylene-ethynylene) (OPE), was deposited as thin films by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) on solid substrates and exhibited light-induced biocidal activity. The biocidal activity ... Full text Cite

Tuning the refractive index of homopolymer blends by controlling nanoscale domain size via RIR-MAPLE deposition

Journal Article Macromolecular Chemistry and Physics · December 1, 2013 Anti-reflection (AR) coatings designed for glass and other rigid, inorganic substrates are commercially available; however, these inorganic AR coatings tend to crack or delaminate on flexible substrates. A polymeric film with a gradient refractive index (G ... Full text Cite

Characterization of colloidal quantum dot ligand exchange by X-ray photoelectron spectroscopy

Journal Article Journal of Electronic Materials · May 1, 2013 Colloidal quantum dots (CQDs) are chemically synthesized semiconductor nanoparticles with size-dependent wavelength tunability. Chemical synthesis of CQDs involves the attachment of long organic surface ligands to prevent aggregation; however, these ligand ... Full text Cite

RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

Journal Article AIP Conference Proceedings · December 1, 2012 Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host m ... Full text Cite

Enhanced dispersion of CdSe/MEH-CN-PPV hybrid nanocomposites by in situ polymerization using AEM as photopolymerizable precursor

Journal Article Colloid and Polymer Science · October 1, 2012 Colloidal quantum dots (CQDs) can easily become aggregated when blended in a polymer matrix. Although several techniques have been reported to prepare dispersed CQDs in a polymer matrix, the novel approach of this work is to obtain well-dispersed CQD-polym ... Full text Cite

Effects of emulsion-based resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) on the molecular weight of polymers

Journal Article Polymers · June 8, 2012 The molecular weight of a polymer determines key optoelectronic device characteristics, such as internal morphology and charge transport. Therefore, it is important to ensure that polymer deposition techniques do not significantly alter the native polymer ... Full text Cite

Tuning the refractive index of blended polymer films by RIR-MAPLE deposition

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · March 23, 2012 Graded index polymer films enable novel optics using rigid or flexible substrates, such as waveguides or anti-reflection coatings. Previously, such films have been fabricated by nanoimprint lithography or the decomposition of a single component in polymer ... Full text Cite

Theoretical investigation of intraband, infrared absorbance in inorganic/organic nanocomposite thin films with varying colloidal quantum dot surface ligand materials

Journal Article International Journal of High Speed Electronics and Systems · March 1, 2012 Hybrid nanocomposite thin films, composed of inorganic colloidal quantum dots (CQDs) embedded in a matrix of organic conjugated polymer, have shown promise as a method for room-temperature infrared detection due to the three-dimensional confinement of the ... Full text Cite

Influence of semiconductor nanocrystal concentration on polymer hole transport in hybrid nanocomposites

Journal Article Crystals · January 16, 2012 This article investigates hole transport in poly[2-methoxy-5-(2'-ethyl-hexyloxy)- 1,4-phenylene vinylene] (MEH-PPV)/CdSe colloidal quantum dot (CQD) nanocomposites using a modified time-of-flight photoconductivity technique. The measured hole drift mobilit ... Full text Cite

RIR-MAPLE deposition of conjugated polymers for application to optoelectronic devices

Journal Article Applied Physics A: Materials Science and Processing · November 1, 2011 Resonant-infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a promising deposition technology for the fabrication of conjugated polymer-based optoelectronic devices for two primary reasons: (i) the ability to control film morphology, and (ii) ... Full text Cite

Calculation of intraband absorption coefficients in organic/inorganic nanocomposites: Effects of colloidal quantum dot surface ligand and dot size

Journal Article IEEE Journal of Quantum Electronics · October 13, 2011 Hybrid nanocomposite thin films composed of inorganic colloidal quantum dots (CQDs) embedded in an organic conjugated polymer have shown promise as a method for room-temperature infrared detection due to the 3-D confinement of the CQD. The CQDs are coated ... Full text Cite

Quantum-Dot Infrared Photodetectors

Chapter · January 1, 2011 In this chapter, the device physics of quantum-dot infrared photodetectors (QDIPs) is reviewed, including epitaxial growth of quantum-dot (QD)-active regions, intraband transitions in QDs, and infrared photodetector performance parameters. Current QDIP res ... Full text Cite

Resonant infrared matrix-assisted pulsed laser evaporation of inorganic nanoparticles and organic/inorganic hybrid nanocomposites

Journal Article AIP Conference Proceedings · November 29, 2010 In this research, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit different classes of inorganic nanoparticles, including bare, un-encapsulated ZnO and Au nanoparticles, as well as ligand-encapsulated CdSe co ... Full text Cite

Direct measurement of spectrally selective absorption enhancement in Fano resonance photonic crystal cavities on plastic substrates

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · May 7, 2010 We report direct measurement of spectrally selective absorption properties of PbSe and PbS colloidal quantum dots (CQDs) in Si nanomembrane photonic crystal cavities on flexible polyethylene terephthalate (PET) substrates. Enhanced optical absorption was o ... Full text Cite

Colloidal quantum dot absorption enhancement in flexible Fano filters

Journal Article Applied Physics Letters · February 2010 We report here modified absorption property of colloidal quantum dots (CQDs) inside flexible Fano filters-made of patterned single crystalline silicon nanomembrane transferred onto flexible plastic substrates. Enhanced optical absorption was obtained both ... Open Access Cite

Frontiers in semiconductor-based devices

Journal Article JOURNAL OF PHYSICS D-APPLIED PHYSICS · December 7, 2009 Full text Link to item Cite

Controlling the distribution of CdSe colloidal quantum dots in conducting polymer nanocomposite thin films using matrix-assisted pulsed laser evaporation

Journal Article Materials Research Society Symposium Proceedings · December 1, 2009 CdSe colloidal quantum dot (CQD)/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4- phenylenevinylene] (MEH-PPV) nanocomposite thin films were deposited onto ITO-coated glass and carbon grids using two techniques (simultaneous and sequential deposition) of matrix-ass ... Cite

Quantum dot infrared photodetectors: Advantages, challenges, and future research directions

Journal Article 2009 9th IEEE Conference on Nanotechnology, IEEE NANO 2009 · December 1, 2009 Quantum dot infrared photodetectors (QDIPs) are positioned to become an important technology in the field of infrared (IR) detection, particularly for high-temperature, low-cost, high-yield detector arrays required for military applications. By addressing ... Cite

Room-temperature, mid-infrared photodetection in colloidal quantum dot/conjugated polymer hybrid nanocomposites: a new approach to quantum dot infrared photodetectors

Journal Article Journal of Physics D: Applied Physics · November 2009 A unique and distinct approach to unipolar, intraband transitions appropriate for room-temperature, mid- and long-wave-infrared (IR) photodetection is to use active regions comprising colloidal quantum dots (CQDs) synthesized by inorganic chemistry embedde ... Cite

Resonant infrared matrix-assisted pulsed laser evaporation of CdSe colloidal quantum dot/poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyano vinylene)phenylene] hybrid nanocomposite thin films

Journal Article Thin Solid Films · October 30, 2009 CdSe colloidal quantum dot / poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyano vinylene)phenylene] hybrid nanocomposite thin films were deposited using resonant infrared matrix-assisted pulsed laser evaporation. The distributions of CdSe colloidal quantum d ... Full text Cite

Comparison of conjugated polymer deposition techniques by photoluminescence spectroscopy

Journal Article Journal of Vacuum Science and Technology B · October 2009 The effects of various deposition techniques on the photoluminescence spectra of the conjugated polymer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyanovinylene) phenylene] (MEH-CN-PPV) are investigated. Photoluminescence spectroscopy provides insight to t ... Cite

The impact of laser-target absorption depth on the surface and internal morphology of matrix-assisted pulsed laser evaporated conjugated polymer thin films

Journal Article Chemical Physics Letters · August 6, 2009 Poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-(1-cyanovinylene)-phenylene] (MEH-CN-PPV) thin films were deposited using resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) from targets comprising differing ratios of phenol to ice to assess the ... Full text Cite

Quantum-dot infrared photodetectors: A review

Journal Article Journal of Nanophotonics · January 1, 2009 Quantum-dot infrared photodetectors (QDIPs) are positioned to become an important technology in the field of infrared (IR) detection, particularly for high-temperature, low-cost, high-yield detector arrays required for military applications. High-operating ... Full text Cite

Tabletop resonant infrared matrix-assisted pulsed laser evaporation of light-emitting organic thin films

Journal Article IEEE Journal on Selected Topics in Quantum Electronics · July 1, 2008 Structural optimization of light-emitting polymer, or organic semiconductor, thin films deposited by tabletop 2.9 μm resonant infrared matrix-assisted pulsed evaporation (RIR-MAPLE) is investigated. Surface morphology of poly[2-methoxy-5-(2′-ethylhexyloxy) ... Full text Cite

Room-temperature, intraband, infrared absorption in CdSepoly[2-methoxy-5- (2′ -ethylhexyloxy)-1,4-(1-cyanovinylene)phenylene] nanocomposites drop cast on GaAs

Journal Article Journal of Applied Physics · June 9, 2008 We have previously demonstrated a method for achieving room-temperature, intraband, midinfrared (3-5 μm) absorption in CdSe colloidal quantum dotpoly[2-methoxy-5-(2′ -ethylhexyloxy)-1,4- phenylenevinylene] conducting polymer nanocomposites deposited on GaA ... Full text Cite

Doping characterization of InAsGaAs quantum dot heterostructure by cross-sectional scanning capacitance microscopy

Journal Article Applied Physics Letters · March 14, 2008 In order to better understand dopant incorporation in quantum dot infrared photodetectors, the application of cross-sectional scanning capacitance microscopy (SCM) has been used to investigate carrier occupation/distribution in a multilayer InAsGaAs quantu ... Full text Cite

Device characterization of CdSe/poly[2-methoxy-5-(2′-ethylhexyloxy)- 1,4-(1-cyanovinylene)phenylene] nanocomposite infrared photodetectors deposited via matrix assisted pulsed laser evaporation on GaAs

Journal Article Materials Research Society Symposium Proceedings · January 1, 2008 The drop-casting of hybrid nanocomposite thin films results in lack of control over film thickness and nanoparticle distribution, thereby posing a serious challenge to achieving high performance infrared photodetectors. In this work, hybrid nanocomposite d ... Full text Cite

Heterogeneous material integration with photonic crystal platforms for nanophotonic devices on foreign substrates

Journal Article ICALEO 2008 - 27th International Congress on Applications of Lasers and Electro-Optics, Congress Proceedings · January 1, 2008 We report our work on nanophotonic devices and the associated fabrication processes, mostly based on the top-down and bottom-up integration of photonic crystal on silicon and other foreign substrates. Encapsulated photonic crystals were proposed based on t ... Full text Cite

Doping effect on carrier occupation and transport in InAs/GaAs quantum dot infrared photodetectors: A capacitance-voltage spectroscopy study

Journal Article Conference on Lasers and Electro-Optics, 2007, CLEO 2007 · December 1, 2007 Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are ... Full text Cite

Doping effect on carrier occupation and transport in InAs/GaAs quantum dot infrared photodetectors: A capacitance-voltage spectroscopy study

Journal Article Conference on Quantum Electronics and Laser Science (QELS) - Technical Digest Series · December 1, 2007 Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are ... Full text Cite

Characteristics of photonic crystal cavity based infrared photodetectors

Journal Article Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS · December 1, 2007 Full text Cite

Doping characterization of InAs/GaAs quantum dot heterostructure by cross-sectional scanning capacitance microscopy

Journal Article Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS · December 1, 2007 Cross-section of multi-layer InAs/GaAs quantum dot heterostructure has been characterized using scanning capacitance microscopy to investigate dopant incorporation into quantum dots. Simulation of the corresponding band structure is used to better understa ... Full text Cite

Probing dopant incorporation in InAs/GaAs QDIPs by polarization-dependent Fourier transform infrared spectroscopy

Journal Article Infrared Physics and Technology · October 1, 2007 In order to improve spectral response tunability of quantum-dot infrared photodetectors (QDIPs), it is critical to understand how dopants are incorporated into quantum dots (QDs). In this letter, polarization-dependent Fourier transform infrared spectrosco ... Full text Cite

Effect of donor-complex-defect-induced dipole field on InAs/GaAs quantum dot infrared photodetector activation energy

Journal Article Applied Physics Letters · June 28, 2007 In order to understand dopant incorporation in quantum dot infrared photodetectors, three quantum dot (QD) Schottky diodes (undoped, delta doped, and modulation doped) have been investigated. Donor-complex-defect (DX) centers have been observed by photocap ... Full text Cite

DX -like centers in InAsGaAs QDIPs observed by polarization-dependent Fourier transform infrared spectroscopy

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · June 11, 2007 In order to decrease dark current density and improve spectral response tunability of quantum dot infrared photodetectors (QDIPs), it is critical to understand how dopants are incorporated into quantum dot active regions. In this article, polarization-depe ... Full text Cite

Hybrid nanomaterials for multi-spectral infrared photodetection

Journal Article International Journal of High Speed Electronics and Systems · March 1, 2007 Quantum dot infrared photodetectors (QDIPs) using quantum dots (QDs) grown by strained-layer epitaxy have demonstrated low dark current, multi-spectral response, high operating temperature, and infrared (IR) imaging. However, achieving near room-temperatur ... Full text Cite

Doping effect on carrier occupation and transport in InAs/GaAs quantum dot infrared photodetectors: A capacitance-voltage spectroscopy study

Journal Article Optics InfoBase Conference Papers · January 1, 2007 Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are ... Cite

Doping effect on carrier occupation and transport in InAs/GaAs quantum dot infrared photodetectors: A capacitance-voltage spectroscopy study

Journal Article Optics InfoBase Conference Papers · January 1, 2007 Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are ... Cite

Doping effect on carrier occupation and transport in InAs/GaAs quantum dot infrared photodetectors: A capacitance-voltage spectroscopy study

Journal Article Optics InfoBase Conference Papers · January 1, 2007 Impurity centers induced by dopants in InAs/GaAs quantum-dot systems affect energy level occupation and carrier transport in multi-layer QDIPs. In order to better understand doping effects and to optimize device performance, capacitance-voltage spectra are ... Cite

Fourier transform infrared absorbance and photoluminescence spectroscopy studies of CdSe colloidal quantum dot/conducting polymer nanocomposites for application to infrared photodetectors

Journal Article Materials Research Society Symposium Proceedings · January 1, 2007 In this paper we investigate the optical properties of four CdSe colloidal quantum dot/conducting polymer nanocomposites deposited on GaAs substrates using photoluminescence and Fourier transform infrared absorbance. The purpose of this investigation is to ... Full text Cite

Mid-infrared quantum dot photodetectors

Journal Article Springer Series in Optical Sciences · December 11, 2006 Full text Cite

Quantum dots in semiconductor optoelectronic devices

Journal Article Electrochemical Society Interface · December 1, 2006 Both wet and dry semiconductor quantum dots (SQD) will be effectively incorporated into optoelectronic devices to improve performance and enable higher efficiency photodetectors and emitters. These nanoscale materials have electronic and optical properties ... Cite

Control of dopant incorporation in InAs/GaAs quantum dots for infrared photodetection with low dark current

Journal Article Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006 · December 1, 2006 To reduce dark current in quantum-dot infrared photodetectors, different InAs/GaAs quantum-dot doping conditions, i.e. concentration and modulation- vs. delta-doping, have been investigated by the comparison of temperature-dependent dark current and corres ... Full text Cite

Optical characterization of CdSe colloidal quantum dot/ MEH-PPV polymer nanocomposites spin-cast on GaAs substrates

Journal Article Materials Research Society Symposium Proceedings · January 1, 2006 The motivation and distinct approach for this work is the use of intraband transitions within colloidal quantum dots for the detection of mid- (3-5 μm) and/or long-wave (8-14 μm) infrared light. The CdSe colloidal quantum dot/MEH-PPV conducting polymer nan ... Full text Cite

Ultrafast electronic dynamics in unipolar n-doped InAs/GaAs quantum dot structures

Journal Article Quantum Electronics and Laser Science Conference (QELS) · October 31, 2005 Time-resolved mid-infrared-pump, optical-probe differential transmission spectroscopy on n-doped quantum dots directly reveals electron dynamics relevant to unipolar devices. Capture times into excited and ground states are found to be 7.1 and 116 ps. © 20 ... Cite

High-performance mid-infrared quantum dot infrared photodetectors

Journal Article Journal of Physics D: Applied Physics · July 7, 2005 Quantum dot infrared photodetectors (QDIPs) have emerged as attractive devices for sensing long wavelength radiation. Their principle of operation is based on intersublevel transitions in quantum dots (QDs). Three-dimensional quantum confinement offers the ... Full text Cite

Research propels quantum dots forward

Journal Article Laser Focus World · May 1, 2005 The challenges faced by the quantum-dot IR photodetectors (QDIP), which are well-suited for detecting mid-IR light at elevated temperatures, are discussed. The quantum-mechanical nature of the QD for IR photodetectors allows normal-incidence detection, lar ... Cite

Ultrafast electronic dynamics in unipolar n-doped InAs/GaAs quantum dot structures

Journal Article Optics InfoBase Conference Papers · January 1, 2005 Time-resolved mid-infrared-pump, optical-probe differential transmission spectroscopy on n-doped quantum dots directly reveals electron dynamics relevant to unipolar devices. Capture times into excited and ground states are found to be 7.1 and 116 ps. © 20 ... Cite

Resonant tunneling quantum dot infrared photodetector (RT-QDIP): Separating dark current and photocurrent

Journal Article Device Research Conference - Conference Digest, DRC · December 1, 2004 The reduction of dark current in quantum dot (QD) infrared photodetectors (QDIP), which uses resonant tunneling (RT) barriers to selectively block dark current while transmitting photocurrent, was investigated. A heterostructure design for such a RT-QDIP c ... Full text Cite

Quantum dot opto-electronic devices

Journal Article Annual Review of Materials Research · September 6, 2004 Highly strained semiconductors grow epitaxially on mismatched substrates in the Stranski-Krastanow growth mode, wherein islands are formed after a few monolayers of layer-by-layer growth. Elastic relaxation on the facet edges, renormalization of the surfac ... Full text Cite

Quantum dot infrared photodetector design based on double-barrier resonant tunnelling

Journal Article Electronics Letters · August 19, 2004 A novel quantum dot infrared photodeteotor design, based on double-barrier resonant tunnelling, is proposed and demonstrated. Theoretical calculations predict significantly lower dark currents in this device, compared to conventional quantum dot photodetec ... Full text Cite

High-temperature operation of InAs-GaAs quantum-dot infrared photodetectors with large responsivity and detectivity

Journal Article IEEE Photonics Technology Letters · May 1, 2004 We have optimized the growth of multiple (40-70) layers of self-organized InAs quantum dots separated by GaAs barrier layers in order to enhance the absorption of quantum-dot infrared photodetectors (QDIPs). In devices with 70 quantum-dot layers, at relati ... Full text Cite

Contribution of Field-Assisted Tunneling Emission to Dark Current in InAs-GaAs Quantum Dot Infrared Photodetectors

Journal Article IEEE Photonics Technology Letters · March 1, 2004 A model for the dark current in quantum dot infrared photodetectors, including thermionic emission and field-assisted tunneling, is developed. The calculated dark currents are in excellent agreement with measured values for a wide range of temperatures (78 ... Full text Cite

High responsivity AIAs/InAs/GaAs superlattice quantum dot infrared photodetector

Journal Article Electronics Letters · February 5, 2004 The characteristics of quantum dot infrared photodetectors (QDIPs) in which InAs self-organised quantum dots are embedded in an AlAs/GaAs superlattice matrix are reported. An extremely large peak responsivity, R p =2.5 A/W, is measured at T= 78K for Vvias ... Full text Cite

Heterostructures for achieving large responsivity in InAs/GaAs quantum dot infrared photodetectors

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · January 1, 2004 Full text Cite

Tailoring of quantum dot infrared photodetector performance with AlAs/GaAs superlattice barriers

Journal Article Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS · December 9, 2003 Quantum dot infrared photodetectors (QDIPs) offer normal-incidence sensitivity, low dark current, high-temperature operation, and multi-wavelength detection. In general, the advantages of these intersubband devices are the result of three-dimensional quant ... Cite

Carrier dynamics in self-organized in(Ga)As/Ga(Al)as quantum dots and their application to long-wavelength sources and detectors

Journal Article Institute of Physics Conference Series · December 1, 2003 The unique hot-carrier dynamics and intersubband transitions in quantum dots play important roles in defining the device characteristics for mid- and far-infrared sources and detectors. The properties of these devices are described and discussed. ... Cite

Influence of rapid thermal annealing on a 30 stack InAs/GaAs quantum dot infrared photodetector

Journal Article Journal of Applied Physics · October 15, 2003 Influence of rapid thermal annealing on a 30 stack InAs/GaAs quantum dot infrared photodetector (QDIP) was studied. Temperatures in the range of 600-800°C for 60 s, typical of atomic interdiffusion were used. The devices exhibited large dark currents after ... Full text Cite

Intersubband absorption in annealed InAs/GaAs quantum dots: A case for polarization-sensitive infrared detection

Journal Article Journal of Physics D: Applied Physics · August 7, 2003 We have studied the characteristics of intersubband absorption of polarized infrared (IR) radiation in as-grown and annealed self-organized InAs/GaAs quantum dots. It is observed that with the increase of annealing time and temperature, the dots tend to fl ... Full text Cite

Absorption, carrier lifetime, and gain in InAs-GaAs quantum-dot infrared photodetectors

Journal Article IEEE Journal of Quantum Electronics · March 1, 2003 Quantum-dot infrared photodetectors (QDIPs) are being studied extensively for mid-wavelength and long-wavelength infrared detection because they offer normal-incidence, high-temperature, multispectral operation. Intersubband absorption, carrier lifetime, a ... Full text Cite

High responsivity, polarization-sensitive, 70-layer InAs/GaAs quantum dot infrared photodetector

Conference Optics InfoBase Conference Papers · January 1, 2003 Excellent material and optical quality of a 70-layer quantum dot infrared photodetector has enabled high responsivity detection and polarization-sensitive absorption. ... Cite

High responsivity, polarization-sensitive, 70-layer InAs/GaAs quantum dot infrared photodetector

Journal Article OSA Trends in Optics and Photonics Series · January 1, 2003 The material characteristics of 70-layer quandom dot infrared photodetector (QDIP) was investigated using transmission electron microscopy and photoluminescence measurements. QDIP comprises of InAs/GaAs quantum dots, which offers nornal incidence, low dark ... Cite

Two photon absorption in quantum dot infrared photodetector

Journal Article OSA Trends in Optics and Photonics Series · January 1, 2003 We experimentally observed for the first time two-photon detection in a quantum dot mid-infrared photodetector. We use a 100-fs difference frequency generator tuned in the 2-5 micron range. The photodetector is suitable for second-order autocorrelation mea ... Cite

Mechanisms of lateral ordering of InAs/GaAs quantum dot superlattices

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · January 1, 2003 Full text Cite

Quantum dot infrared detectors and sources

Journal Article International Journal of High Speed Electronics and Systems · December 1, 2002 InAs/GaAs quantum dot devices have the potential to be the leading technology for infrared detection and emission, which are necessary for many military and domestic applications. Quantum dot infrared photodetectors yield higher operating temperatures, low ... Full text Cite

Raster-scan imaging with normal-incidence, midinfrared InAs/GaAs quantum dot infrared photodetectors

Journal Article Applied Physics Letters · May 6, 2002 We demonstrate normal incidence infrared imaging with quantum dot infrared photodetectors using a raster-scan technique. The device heterostructure, containing multiple layers of InAs/GaAs self-organized quantum dots, were grown by molecular-beam epitaxy. ... Full text Cite

Low-bias, high-temperature performance of a normal-incidence InAs/GaAs vertical quantum-dot infrared photodetector with a current-blocking barrier

Journal Article Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures · May 1, 2002 The properties of a low-bias and high-temperature InAs/GaAs vertical quantum-dot infrared photodetector (QDIP) with a single Al0.3Ga0.7As current-blocking barrier were investigated. This device demonstrated high peak detectivity and a high operating temper ... Full text Cite

Hot dot detectors

Journal Article IEEE Circuits and Devices Magazine · January 1, 2002 The properties of normal-incidence, high-temperature, mid-wavelength IR, InAs/GaAs vertical QDIPs with and without an Al 0.3Ga 0.7As current-blocking barrier are discussed. These devices demonstrate very high D* values (D* ∼3 × 10 9 cmHz 1/2/W at T = 100 K ... Full text Cite

Quantum dot infrared photodetectors

Journal Article Proceedings of SPIE-The International Society for Optical Engineering · January 1, 2002 Mid-and far-infrared detectors operating at elevated temperatures (T > 150 K) are critical for imaging applications. In(Ga)As/GaAs quantum dots, grown by self-organized epitaxy, are an important material for the design and fabrication of high-temperature i ... Full text Cite

Quantum dot long-wavelength detectors

Journal Article Materials Research Society Symposium - Proceedings · January 1, 2002 Long-wavelength infrared detectors operating at elevated temperatures are critical for imaging applications. InAs/GaAs quantum dots are an important material for the design and fabrication of high-temperature infrared photodetectors. Quantum dot infrared p ... Cite

Strain relaxation in rapid thermally annealed InAs/GaAs quantum dot infrared photodetectors

Journal Article Conference on Optoelectronic and Microelectronic Materials and Devices, Proceedings, COMMAD · January 1, 2002 In this paper the effect of rapid thermal annealing (RTA) on a 30 stacked InAs/GaAs, molecular beam epitaxially grown quantum dot infrared detector (QDIP) device is studied. Temperatures in the range of 700 - 900°C for 60s, typical of ion implantation indu ... Full text Cite

Normal-incidence, high-temperature, mid-infrared, inAs-GaAs vertical quantum-dot infrared photodetector

Journal Article IEEE Journal of Quantum Electronics · November 1, 2001 The growth, fabrication, and characterization of a normal-incidence, high-temperature, mid-wavelength infrared, InAs - GaAs vertical quantum-dot infrared photodetector with a single Al0.3Ga0.7As current-blocking barrier are described and discussed in detai ... Full text Cite

High-detectivity, normal-incidence, mid-infrared (λ∼4μm)inAs/GaAs quantum-dot detector operating at 150 k

Journal Article Applied Physics Letters · July 16, 2001 A mid-infrared normal-incidence InAs/GaAs quantum-dot detector containing Al0.3Ga0.7As with peak responsivity and a very high peak detectivity was studied. The detectors were grown, fabricated and characterized in the temperature range of 78 to 150 K. The ... Full text Cite

Broadcasting a single wavelength over a WDM network

Journal Article Conference on Optical Fiber Communication, Technical Digest Series · January 1, 2001 We propose and demonstrate a wavelength-division-multiplexed network in which one wavelength is used for broadcast signals, while other wavelengths are used for switched signals. A novel device-the Bragg tap-is demonstrated. ... Cite

High-temperature operation of mid-infrared (λ=4-5 μm) vertical and lateral InAs/GaAs/AlGaAs quantum dot infrared photodetectors

Journal Article Annual Device Research Conference Digest · January 1, 2001 State-of-the-art results on vertical and lateral mid-infrared intersubband quantum dot infrared photodetectors (QDIP) was presented. The vertical detectors exhibited lowest dark currents for such devices and also had one of the highest operating temperatur ... Cite

Exploration of Solvent Effects On Morphology of Polyaniline & Other Polymer Films Deposited Through RIR- MAPLE

Conference Through the use of aromatic solvents with varying numbers of hydroxyl and methyl moieties, there is an opportunity to positively impact morphology of polymer films deposited through emulsion-based Resonant-Infrared Matrix-Assisted Pulsed Laser Evaporation ... Full text Open Access Cite