Localized excitons mediate defect emission in ZnO powders

Journal Article

A series of continuous-wave spectroscopic measurements elucidates the mechanism responsible for the technologically important green emission from deep-level traps in ZnO:Zn powders. Analysis of low-temperature photoluminescence (PL) and PL excitation spectra for bound excitons compared to the temperature-dependent behavior of the green emission reveals a deep correlation between green PL and specific donor-bound excitons. Direct excitation of these bound excitons produces highly efficient green emission from near-surface defects. When normalized by the measured external quantum efficiency, the integrated PL for both excitonic and green emission features grows identically with excitation intensity, confirming the strong connection between green emission and excitons. The implications of these findings are used to circumscribe operational characteristics of doped ZnO-based white light phosphors whose quantum efficiency is almost twice as large when the bound excitons are directly excited. © 2013 American Institute of Physics.

Full Text

Duke Authors

Cited Authors

  • Foreman, JV; Simmons, JG; Baughman, WE; Liu, J; Everitt, HO

Published Date

  • April 7, 2013

Published In

Volume / Issue

  • 113 / 13

International Standard Serial Number (ISSN)

  • 0021-8979

Digital Object Identifier (DOI)

  • 10.1063/1.4798359

Citation Source

  • Scopus