title: Fabrication of wide-bandgap transparent electrodes by using conductive filaments: performance breakthrough in vertical-type GaN LED.
abstract: For realizing next-generation solid-state lighting devices, performance breakthroughs must be accomplished for nitride-based light-emitting diodes (LEDs). Highly transparent conductive electrodes (TCEs) may be key to achieving this goal, as they provide uniform current injection and distribution across a large device area, eventually increasing the light output power. However, the trade-off between electrical conductivity and optical transmittance of LEDs must be addressed. Herein, we introduce a novel strategy based on TCEs fabricated using wide-bandgap (WB) materials such as SiNx, incorporated beneath the n-type electrode of vertical-type LEDs, and show the feasibility of this strategy. We employ a novel electrical breakdown (EBD) technique to form conductive filaments (or current paths) between a TCE and n-GaN (GaN: gallium nitride). By employing the EBD process, we obtain both ohmic behavior for SiNx TCE/n-GaN and a current spreading effect across n-GaN. These results demonstrate the tremendous potential of WB-TCEs for use in high-performance optoelectronic devices.
authors: School of Electrical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors: Su Jin
authors: SJ
authors: Kim
authors: School of Electrical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors: Hee-Dong
authors: HD
authors: Kim
authors: School of Electrical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors: Kyeong Heon
authors: KH
authors: Kim
authors: School of Electrical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors: Hee Woong
authors: HW
authors: Shin
authors: Nano Device Research Center, Korea Institute of Science and Technology, Seoul, 136-791, Republic of Korea.
authors: Il Ki
authors: IK
authors: Han
authors: School of Electrical Engineering, Korea University, Anam-dong 5-ga, Sungbuk-gu, Seoul 136-701, Republic of Korea.
authors: Tae Geun
authors: TG
authors: Kim