Shockley-Read-Hall and Auger non-radiative recombination in GaN based LEDs A size effect study

Francois Olivier (1, 2) , Anis Daami (1) , Christophe Licitra (1) , Francois Templier (1)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 III-V Lab - Alcatel-Thales III-V Lab

GaN-based micro light-emitting diode (mu LED) arrays are very promising devices for display applications. In these arrays, each mu LED works as a single pixel of a whole image. The electro-optical performance of these mu LEDs is an important subject to study. Here, we investigate the influence of LED size on the radiative and non-radiative recombination. The standard ABC model has been widely used to describe the efficiency of GaN based LEDs. Using this model, we extract A, B, and C coefficients for various LED sizes, showing how the competition between radiative and non-radiative recombination processes varies with the LED geometry. Time-resolved photoluminescence allows us to determine coefficient B, related to radiative recombination. Through current-voltage-luminance characterizations, we determine parameters A and C related to Shockley-Read-Hall and Auger recombination. We find that coefficient A is strongly dependent on LED size, indicating a drastic effect of sidewall defects on the performance of LEDs. On the other hand, coefficient C is independent of LED size. This latter result demonstrates that efficiency droop does not depend on LED size.

Domaines: Sciences de l'ingénieur [physics]

Francois Olivier, Anis Daami, Christophe Licitra, Francois Templier. Shockley-Read-Hall and Auger non-radiative recombination in GaN based LEDs A size effect study. Applied Physics Letters, 2017, 111 (2), pp.022104. ⟨10.1063/1.4993741⟩. ⟨cea-02202427⟩