TY - JOUR
T1 - Performance Improvement of GaN-Based Light-Emitting Diodes with a Microhole Array, 45° Sidewalls, and a SiO2 Nanoparticle/Microsphere Passivation Layer
AU - Chang, Ching Hong
AU - Lee, Yu Lin
AU - Wang, Zih Fong
AU - Liu, Rong Chau
AU - Tsai, Jung Hui
AU - Liu, Wen Chau
N1 - Funding Information:
Manuscript received August 16, 2018; revised October 10, 2018 and November 12, 2018; accepted November 19, 2018. Date of publication December 11, 2018; date of current version December 24, 2018. This work was supported in part by the Ministry of Science and Technology of the Republic of China under Contract MOST-106-2221-E-006-224 and in part by the Advanced Optoelectronic Technology Center, National Cheng Kung University. The review of this paper was arranged by Editor J. Huang. (Corresponding author: Wen-Chau Liu.) C.-H. Chang, Y.-L. Lee, Z.-F. Wang, and W.-C. Liu are with the Department of Electrical Engineering, Institute of Microelectronics, National Cheng Kung University, Tainan 70101, Taiwan (e-mail: wcliu@ mail.ncku.edu.tw).
Publisher Copyright:
© 1963-2012 IEEE.
PY - 2019/1
Y1 - 2019/1
N2 - The characteristics of GaN-based light-emitting diodes (LEDs) with a hybrid structure incorporating a microhole array, 45 sidewalls, and an appropriate SiO2 nanoparticle (NP)/microsphere (MSs) passivation layer are studied and reported. The use of a SiO2 NP/MSs passivation layer causes a remarkable reduction in reverse-biased leakage current. The employment of this hybrid structure leads to substantial enhancements in optical properties without any degradation in electrical performance. In addition, a lower content of SiO2 NP in the mixed SiO2 NP/MSs solution leads to enhanced optical behavior due to the improved transmittance. Experimentally, as compared with a conventional LED (Device A), the studied Device E shows 50.6%, 50.9%, 48.4%, and 49.9% enhancements in light output power, luminous flux, luminous efficacy, and wall-plug efficiency, respectively. These advantages are mainly attributed to the increased scattering probability and the opportunity to find photon escape cones as well as the reduced total internal reflection and Fresnel reflection effects. Therefore, the studied hybrid structure provides a promise for high-performance GaN-based LED applications.
AB - The characteristics of GaN-based light-emitting diodes (LEDs) with a hybrid structure incorporating a microhole array, 45 sidewalls, and an appropriate SiO2 nanoparticle (NP)/microsphere (MSs) passivation layer are studied and reported. The use of a SiO2 NP/MSs passivation layer causes a remarkable reduction in reverse-biased leakage current. The employment of this hybrid structure leads to substantial enhancements in optical properties without any degradation in electrical performance. In addition, a lower content of SiO2 NP in the mixed SiO2 NP/MSs solution leads to enhanced optical behavior due to the improved transmittance. Experimentally, as compared with a conventional LED (Device A), the studied Device E shows 50.6%, 50.9%, 48.4%, and 49.9% enhancements in light output power, luminous flux, luminous efficacy, and wall-plug efficiency, respectively. These advantages are mainly attributed to the increased scattering probability and the opportunity to find photon escape cones as well as the reduced total internal reflection and Fresnel reflection effects. Therefore, the studied hybrid structure provides a promise for high-performance GaN-based LED applications.
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U2 - 10.1109/TED.2018.2882802
DO - 10.1109/TED.2018.2882802
M3 - Article
AN - SCOPUS:85058613759
SN - 0018-9383
VL - 66
SP - 505
EP - 511
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
IS - 1
M1 - 8573125
ER -