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


Journal Article

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, and gain are parameters that need to be better characterized, understood, and controlled in order to realize high-performance QDIPs. An eight-band k · p model is used to calculate polarization-dependent intersubband absorption. The calculated trend in absorption has been compared with measured data. In addition, a Monte-Carlo simulation is used to calculate the effective carrier lifetime in detectors, allowing the calculation of gain in QDIPs as a function of bias. The calculated gain values can be fitted well with experimental data, revealing that the gain in these devices consists of two mechanisms: Photoconductive gain and avalanche gain, where the latter is less dominant at normal operating biases.

Full Text

Duke Authors

Cited Authors

  • Kochman, B; Stiff-Roberts, AD; Chakrabarti, S; Phillips, JD; Krishna, S; Singh, J; Bhattacharya, P

Published Date

  • March 1, 2003

Published In

Volume / Issue

  • 39 / 3

Start / End Page

  • 459 - 467

International Standard Serial Number (ISSN)

  • 0018-9197

Digital Object Identifier (DOI)

  • 10.1109/JQE.2002.808169

Citation Source

  • Scopus