Katsuro Sae, Lu Weifang, Ito Kazuma, Nakayama Nanami, Yamamura Shiori, Jinno Yukimi, Inaba Soma, Shima Ayaka, Sone Naoki, Han Dong-Pyo, Huang Kai, Iwaya Motoaki, Takeuchi Tetsuya, Kamiyama Satoshi
Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan.
Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, Department of Physics, Xiamen University, Xiamen 361005, China.
Nanophotonics. 2022 Sep 28;11(21):4793-4804. doi: 10.1515/nanoph-2022-0388. eCollection 2022 Dec.
GaInN/GaN multi-quantum-shell (MQS) nanowires (NWs) are gaining increasing attention as promising materials for developing highly efficient long-wavelength micro-light emitting diodes (LEDs). To improve the emission properties in GaInN/GaN MQS NWs, it is necessary to suppress the emission from the (0001) -plane MQS at the apex region, which featured with low crystalline quality. In this study, we investigated the enhancement of optical properties and the realization of micro-LEDs by confirming the effect of the (0001) plane region. A 7.9-fold enhancement of the electroluminescence (EL) intensity was demonstrated by removal the (0001) plane region via inductively coupled plasma (ICP) dry etching, owing to the promoted current injection into the (1-101) semi-polar and (10-10) non-polar sidewall area. To investigate the effect of the emission area on the samples with and without truncated (0001) plane region, devices with three different mesa areas (50 × 50, 100 × 100, and 100 × 200 μm) were fabricated. An increased EL intensity with the reduced mesa areas was observed in the samples without dry etching of the (0001)-plane area, because more current can be injected into the sidewall region with higher crystalline quality and luminous efficiency than the (0001)-plane MQS. Under the same injection current density, the truncated samples' light output was increased for more than ten times as compared to the samples without (0001)-plane etching. Therefore, it confirms the possibility of realizing highly efficient GaInN/GaN MQS NWs LEDs by eliminating the (0001) plane MQS region. A precise etching and surface passivation of the apex region is expected to further reduce the reverse leakage current and improve the performance in NW-LEDs.
氮化镓铟/氮化镓多量子壳（MQS）纳米线（NWs）作为开发高效长波长微发光二极管（LED）的有前景材料正受到越来越多的关注。为了改善氮化镓铟/氮化镓MQS纳米线的发光特性，有必要抑制顶部区域具有低结晶质量的（0001）面MQS的发光。在本研究中，我们通过确认（0001）面区域的影响来研究光学特性的增强和微发光二极管的实现。通过电感耦合等离子体（ICP）干法蚀刻去除（0001）面区域，实现了电致发光（EL）强度提高7.9倍，这是由于促进了电流注入到（1-101）半极性和（10-10）非极性侧壁区域。为了研究有无截断（0001）面区域的样品中发光面积的影响，制备了具有三种不同台面面积（50×50、100×100和100×200μm）的器件。在未对（0001）面区域进行干法蚀刻的样品中，观察到台面面积减小，EL强度增加，因为与（0001）面MQS相比，更多电流可以注入到具有更高结晶质量和发光效率的侧壁区域。在相同的注入电流密度下，与未进行（0001）面蚀刻的样品相比，截断样品的光输出增加了十多倍。因此，证实了通过消除（0001）面MQS区域实现高效氮化镓铟/氮化镓MQS纳米线发光二极管的可能性。预计对顶部区域进行精确蚀刻和表面钝化将进一步降低反向漏电流并提高纳米线发光二极管的性能。
