Open AccessEffect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells
Author(s) -
Rachel May Barrett,
Rubén Ahumada-Lazo,
Juan Arturo Alanis,
Patrick Parkinson,
Stephen Church,
Menno J. Kappers,
Rachel A. Oliver,
David J. Binks
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1919/1/012011
Subject(s) - voltage droop , photoluminescence , materials science , quantum well , light emitting diode , emission intensity , optoelectronics , power density , optics , physics , power (physics) , laser , quantum mechanics , voltage divider
Micro-photoluminescence maps reveal micron-scale spatial variation in intensity, peak emission energy and bandwidth across InGaN/GaN quantum wells. To investigate the effect of this spatial variation on measurements of the dependence of emission efficiency on carrier density, excitation power-dependent emission was collected from a bright and dark region on each of blue-and green emitting samples. The onset of efficiency droop was found to occur at a greater carrier density in the dark regions than in the bright, by factors of 1.2 and 1.8 in the blue and green-emitting samples, respectively. By spatially integrating the emission from progressively larger areas, it is also shown that collection areas greater than ∼50 μm in diameter are required to reduce the intensity variation to less than 10%.