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n-type GaN surface etched green light-emitting diode to reduce non-radiative recombination centers

Authors :
Motoaki Iwaya
Isamu Akasaki
Satoshi Kamiyama
Ryo Takahashi
Tetsuya Takeuchi
Dong-Pyo Han
Shintaro Ueda
Weifang Lu
Ryoto Fujiki
Yusuke Ueshima
Source :
Applied Physics Letters. 118:021102
Publication Year :
2021
Publisher :
AIP Publishing, 2021.

Abstract

In this study, we attempt to identify the presence of surface defects (SDs) at an n-type GaN surface after high-temperature growth and gain insight into their intrinsic features. To this end, first, we carefully investigate n-type GaN samples with different surface etching depths. Low-temperature photoluminescence (PL) spectra reveal that SDs are most likely nitrogen vacancies (VN) and/or VN-related point defects intensively distributed within ∼100 nm from the n-type GaN surface after a high-temperature growth. We investigate the effect of SDs on the internal quantum efficiency (IQE) of green light-emitting diodes (LEDs) by preparing GaInN-based green LEDs employing a surface-etched n-type GaN, which exhibits a prominent enhancement of the PL efficiency with an increase in the etching depth. This effect is attributable to the reduced non-radiative recombination centers in multiple-quantum-well active regions because the SDs near the n-type GaN surface are removed by etching. We discuss strategies of in situ engineering on SDs to further improve the IQE in GaInN-based green LEDs on the basis of the results presented in this study.

Details

ISSN :
10773118 and 00036951
Volume :
118
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........4df3396e1bdb6475a1a5dde42212a2e3