Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5kAcm−2

Tian, Pengfei and Althumali, Ahmad and Gu, Erdan and Watson, Ian M. and Dawson, Martin D. and Liu, Ran (2016) Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5kAcm−2. Semiconductor Science and Technology, 31 (4). pp. 1-12. ISSN 0268-1242 (https://doi.org/10.1088/0268-1242/31/4/045005)

[thumbnail of Tian-etal-SST2016-aging-characteristics-of-blue-ingan-micro-light-emitting-diodes] Text. Filename: Tian_etal_SST2016_aging_characteristics_of_blue_ingan_micro_light_emitting_diodes.pdf
Accepted Author Manuscript

Download (745kB)

Abstract

The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm−2 for emerging microLED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC.

ORCID iDs

Tian, Pengfei, Althumali, Ahmad, Gu, Erdan ORCID logoORCID: https://orcid.org/0000-0002-7607-9902, Watson, Ian M. ORCID logoORCID: https://orcid.org/0000-0002-8797-3993, Dawson, Martin D. ORCID logoORCID: https://orcid.org/0000-0002-6639-2989 and Liu, Ran;