| 학회 | 한국재료학회 |
| 학술대회 | 2007년 가을 (11/02 ~ 11/02, 성균관대학교) |
| 권호 | 13권 2호 |
| 발표분야 | 반도체재료 |
| 제목 | Effect of introducing nano-imprinted Sb-doped SnO2 transparent conducting oxide layer on the improvement of the light output of GaN-based LEDs |
| 초록 | LEDs are regarded as a strong candidate for replacing preexisting light sources. To make such devices, p-type ohmic contact layers with low specific contact resistance, high transparency are needed. In addition to that, an improvement of light extraction efficiency is also needed. Still, external quantum efficiency is very low as compared to internal quantum efficiency and it is the main obstacle for LEDs to become next-generation general lighting sources. One of the reasons is the large difference of refractive indices between GaN-based layers and ambient, resulting in total internal reflection (TIR) of emitted light. In this regard, transparent conducting oxide (TCO) layers are taking important roles to resolve the issue mentioned above. In addition, to further increase light extraction efficiency, several different methods including maskless wet etching, surface relief grating (SRG), holographic lithography has been introduced to induce the diffuse scattering. But, new simple and straightforward methods should be introduced for the high-efficiency, mass-production LED process. In this presentation, we introduced Sb-doped SnO2 (ATO) transparent conducting oxide(TCO) layers on Cu-doped In2O3 (CIO) interlayered p-type electrodes. CIO/ATO p-contacts showed good contact and transparency characteristics. Also, nano-imprint lithography was introduced and shown to be effective in improving light output because of the diffuse scattering of the patterned surface. Possible ohmic mechanisms are discussed based on the results of Auger Electron Spectroscopy(AES), X-ray Electron Spectroscopy(XPS), and Transmission Electron Spectroscopy(TEM). |
| 저자 | 오준호, 홍현기, 나현석, 김용현, 김윤한, 윤주헌, 전준우, 김강원, 이헌, 변경재, 성태연 |
| 소속 | 고려대 |
| 키워드 | Light emitting diode; Transparent conducting oxide; Ohmic contact; nano-imprint lithography |
