Unity quantum efficiency in III-nitride quantum wells at low temperature: Experimental verification by time-resolved photoluminescence

authored by: Philipp Henning, Shawutijiang Sidikejiang, Philipp Horenburg, Heiko Bremers, Uwe Rossow, Andreas Hangleiter
Abstract: Using time-resolved photoluminescence (PL) measurements, we present an experimental verification for 100% internal quantum efficiency (IQE) of III-N quantum wells at low temperatures. Conventional IQE measurements, such as temperature- and power-dependent PL, require a low-temperature normalization, where usually an IQE of 100% is assumed. This assumption neglects remaining nonradiative recombination that may be present even at cryogenic temperatures. From time-resolved PL measurements, the effective charge carrier decay time and the lifetime of radiative recombination can be evaluated separately. We state that the low-temperature IQE of a quantum well corresponds to 100%, whenever the effective charge carrier decay is dominated only by a radiative recombination. In this case, the temperature-dependent measurements show a synchronous rise of the effective lifetimes together with the radiative lifetimes, since only the radiative lifetime increases with temperature in a 2D system. At the same time, nonradiative processes are thermally activated, which results in a decreasing lifetime with temperature. Thereby, absolute IQE measurements become possible, since we provide a robust indicator for the absence of nonradiative recombination in quantum wells at low temperature.
External Organisation(s): Technische Universität Braunschweig
Type: Article
Journal: Applied physics letters
Volume: 119
ISSN: 0003-6951
Publication date: 08.07.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physics and Astronomy (miscellaneous)
Electronic version(s): https://doi.org/10.1063/5.0055368 (Access: Open)

BibTeX

@article{898c6c4509344dc3b356fd54fe41e05c,
title = "Unity quantum efficiency in III-nitride quantum wells at low temperature: Experimental verification by time-resolved photoluminescence",
abstract = "Using time-resolved photoluminescence (PL) measurements, we present an experimental verification for 100% internal quantum efficiency (IQE) of III-N quantum wells at low temperatures. Conventional IQE measurements, such as temperature- and power-dependent PL, require a low-temperature normalization, where usually an IQE of 100% is assumed. This assumption neglects remaining nonradiative recombination that may be present even at cryogenic temperatures. From time-resolved PL measurements, the effective charge carrier decay time and the lifetime of radiative recombination can be evaluated separately. We state that the low-temperature IQE of a quantum well corresponds to 100%, whenever the effective charge carrier decay is dominated only by a radiative recombination. In this case, the temperature-dependent measurements show a synchronous rise of the effective lifetimes together with the radiative lifetimes, since only the radiative lifetime increases with temperature in a 2D system. At the same time, nonradiative processes are thermally activated, which results in a decreasing lifetime with temperature. Thereby, absolute IQE measurements become possible, since we provide a robust indicator for the absence of nonradiative recombination in quantum wells at low temperature.",
author = "Philipp Henning and Shawutijiang Sidikejiang and Philipp Horenburg and Heiko Bremers and Uwe Rossow and Andreas Hangleiter",
year = "2021",
month = jul,
day = "8",
doi = "10.1063/5.0055368",
language = "English",
volume = "119",
journal = "Applied physics letters",
issn = "0003-6951",
publisher = "American Institute of Physics",
number = "1",
}