The efficiency droop in nitride LEDs is currently attributed to either carrier-density-dependent nonradiative recombination or to carrier leakage, both being discussed in terms of a single-particle picture. Our time-resolved photoluminescence results show that the radiative lifetime is independent of carrier density, while the nonradiative lifetime scales with the inverse of the carrier density. This can not be understood in a single-particle model. By means of a many-particle theory approach we obtain a consistent picture with both radiative and Auger recombination enhanced by excitonic electron-hole correlation. In the high carrier density limit single-particle radiative and Auger recombination are recovered.

Date Published: 13 March 2015
PDF: 7 pages
Proc. SPIE 9363, Gallium Nitride Materials and Devices X, 93631R (13 March 2015); doi: 10.1117/12.2078803

Published in SPIE Proceedings Vol. 9363:
Gallium Nitride Materials and Devices X
Jen-Inn Chyi; Hiroshi Fujioka; Hadis Morkoç, Editor(s)