TY - JOUR
T1 - Influences of Microhole Depth and SiO2 Nanoparticle/Microsphere Passivation Layer on the Performance of GaN-Based Light-Emitting Diodes
AU - Wang, Zih Fong
AU - Liu, Wen Chau
N1 - Funding Information:
Manuscript received May 29, 2019; revised July 10, 2019; accepted July 31, 2019. Date of publication August 13, 2019; date of current version September 20, 2019. This work was supported by the Ministry of Science and Technology of the Republic of China under Contract MOST-107-2221-E-006-215. The review of this article was arranged by Editor C. Bayram. (Corresponding author: Wen-Chau Liu.) The authors are with the Institute of Microelectronics, Department of Electrical Engineering, Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (e-mail: [email protected]).
Publisher Copyright:
© 1963-2012 IEEE.
PY - 2019/10
Y1 - 2019/10
N2 - A hybrid structure, including 45° sidewalls, a microhole array, and a thin SiO2 nanoparticle (NP)/microsphere (MS) passivation layer, is used to produce GaN-based light-emitting diodes (LEDs). The influences of the microhole depth and SiO2 NP/MS passivation layer on the LED performance are studied. A shallower depth of a microhole array shows better optical properties due to the complete preservation of the GaN/InGaN multiple quantum well (MQW) region. In addition, the use of a thin SiO2 NP/MS passivation layer gives a remarkably reduced reverse-biased leakage current and improved optical performance. Experimentally, under an injection current density of 110 A/cm2, the studied device, with a proper hybrid structure, shows enhancements of 25.9%, 29.2%, and 29.4% in light output power (LOP), external quantum efficiency (EQE), and wall-plug efficiency, respectively, as compared to a LED device with a deeper depth of microhole array. These improvements are mainly caused by the reduced total internal reflection (TIR) and the Fresnel reflection, which increase scattering probability and the opportunity to find photon escape cones. Hence, the studied hybrid structure in this work is a promising route to fabricate high-performance GaN-based LEDs.
AB - A hybrid structure, including 45° sidewalls, a microhole array, and a thin SiO2 nanoparticle (NP)/microsphere (MS) passivation layer, is used to produce GaN-based light-emitting diodes (LEDs). The influences of the microhole depth and SiO2 NP/MS passivation layer on the LED performance are studied. A shallower depth of a microhole array shows better optical properties due to the complete preservation of the GaN/InGaN multiple quantum well (MQW) region. In addition, the use of a thin SiO2 NP/MS passivation layer gives a remarkably reduced reverse-biased leakage current and improved optical performance. Experimentally, under an injection current density of 110 A/cm2, the studied device, with a proper hybrid structure, shows enhancements of 25.9%, 29.2%, and 29.4% in light output power (LOP), external quantum efficiency (EQE), and wall-plug efficiency, respectively, as compared to a LED device with a deeper depth of microhole array. These improvements are mainly caused by the reduced total internal reflection (TIR) and the Fresnel reflection, which increase scattering probability and the opportunity to find photon escape cones. Hence, the studied hybrid structure in this work is a promising route to fabricate high-performance GaN-based LEDs.
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U2 - 10.1109/TED.2019.2932867
DO - 10.1109/TED.2019.2932867
M3 - Article
AN - SCOPUS:85077734592
SN - 0018-9383
VL - 66
SP - 4211
EP - 4215
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
IS - 10
M1 - 8796386
ER -