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

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
Applied physics letters
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Physics and Astronomy (miscellaneous)
Electronic version(s)
https://doi.org/10.1063/5.0055368 (Access: Open)