skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Quantum efficiency and formation of the emission line in light-emitting diodes based on InGaN/GaN quantum well structures

Abstract

The spectra of electroluminescence, photoluminescence, and photocurrent for the In{sub 0.2}Ga{sub 0.8}N/GaN quantum-well structures are studied to clarify the causes for the reduction in quantum efficiency with increasing forward current. It is established that the quantum efficiency decreases as the emitting photon energy approaches the mobility edge in the In{sub 0.2}Ga{sub 0.8}N layer. The mobility edge determined from the photocurrent spectra is E{sub me} = 2.89 eV. At the photon energies hv > 2.69 eV, the charge carriers can tunnel to nonradiative recombination centers with a certain probability, and therefore, the quantum efficiency decreases. The tunnel injection into deep localized states provides the maximum electroluminescence efficiency. This effect is responsible for the origin of the characteristic maximum in the quantum efficiency of the emitting diodes at current densities much lower than the operating densities. Occupation of the deep localized states in the density-of-states 'tails' in InGaN plays a crucial role in the formation of the emission line as well. It is shown that the increase in the quantum efficiency and the 'red' shift of the photoluminescence spectra with the voltage correlate with the changes in the photocurrent and occur due to suppression of the separation of photogenerated carriers in themore » field of the space charge region and to their thermalization to deep local states.« less

Authors:
; ; ; ; ; ;  [1]
  1. Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)
Publication Date:
OSTI Identifier:
21088455
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 41; Journal Issue: 1; Other Information: DOI: 10.1134/S1063782607010174; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ELECTROLUMINESCENCE; EV RANGE 01-10; GALLIUM NITRIDES; INDIUM NITRIDES; LIGHT EMITTING DIODES; PHOTOLUMINESCENCE; QUANTUM EFFICIENCY; QUANTUM WELLS; SPECTRA

Citation Formats

Bochkareva, N. I., E-mail: n.bochkareva@mail.ioffe.ru, Tarkhin, D. V., Rebane, Yu. T., Gorbunov, R. I., Lelikov, Yu. S., Martynov, I. A., and Shreter, Yu. G. Quantum efficiency and formation of the emission line in light-emitting diodes based on InGaN/GaN quantum well structures. United States: N. p., 2007. Web. doi:10.1134/S1063782607010174.
Bochkareva, N. I., E-mail: n.bochkareva@mail.ioffe.ru, Tarkhin, D. V., Rebane, Yu. T., Gorbunov, R. I., Lelikov, Yu. S., Martynov, I. A., & Shreter, Yu. G. Quantum efficiency and formation of the emission line in light-emitting diodes based on InGaN/GaN quantum well structures. United States. doi:10.1134/S1063782607010174.
Bochkareva, N. I., E-mail: n.bochkareva@mail.ioffe.ru, Tarkhin, D. V., Rebane, Yu. T., Gorbunov, R. I., Lelikov, Yu. S., Martynov, I. A., and Shreter, Yu. G. Mon . "Quantum efficiency and formation of the emission line in light-emitting diodes based on InGaN/GaN quantum well structures". United States. doi:10.1134/S1063782607010174.
@article{osti_21088455,
title = {Quantum efficiency and formation of the emission line in light-emitting diodes based on InGaN/GaN quantum well structures},
author = {Bochkareva, N. I., E-mail: n.bochkareva@mail.ioffe.ru and Tarkhin, D. V. and Rebane, Yu. T. and Gorbunov, R. I. and Lelikov, Yu. S. and Martynov, I. A. and Shreter, Yu. G.},
abstractNote = {The spectra of electroluminescence, photoluminescence, and photocurrent for the In{sub 0.2}Ga{sub 0.8}N/GaN quantum-well structures are studied to clarify the causes for the reduction in quantum efficiency with increasing forward current. It is established that the quantum efficiency decreases as the emitting photon energy approaches the mobility edge in the In{sub 0.2}Ga{sub 0.8}N layer. The mobility edge determined from the photocurrent spectra is E{sub me} = 2.89 eV. At the photon energies hv > 2.69 eV, the charge carriers can tunnel to nonradiative recombination centers with a certain probability, and therefore, the quantum efficiency decreases. The tunnel injection into deep localized states provides the maximum electroluminescence efficiency. This effect is responsible for the origin of the characteristic maximum in the quantum efficiency of the emitting diodes at current densities much lower than the operating densities. Occupation of the deep localized states in the density-of-states 'tails' in InGaN plays a crucial role in the formation of the emission line as well. It is shown that the increase in the quantum efficiency and the 'red' shift of the photoluminescence spectra with the voltage correlate with the changes in the photocurrent and occur due to suppression of the separation of photogenerated carriers in the field of the space charge region and to their thermalization to deep local states.},
doi = {10.1134/S1063782607010174},
journal = {Semiconductors},
number = 1,
volume = 41,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}