High external quantum efficiency (10%) AlGaN-based deep-ultraviolet light-emitting diodes achieved by using highly reflective photonic crystal on p-AlGaN contact layer
| Autor: | Mitsunori Kokubo, Masafumi Jo, Hideki Takagi, Takeshi Iwai, Yukio Kashima, Noritoshi Maeda, Hideki Hirayama, Ryuichiro Kamimura, Yamato Osada, Eriko Matsuura, Toshiro Morita, Takaharu Tashiro |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science business.industry Ultraviolet light emitting diodes General Engineering General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention law 0103 physical sciences Electrode Optoelectronics Contact layer Quantum efficiency Dry etching 0210 nano-technology business Photonic crystal Diode Light-emitting diode |
| Zdroj: | Applied Physics Express. 11:012101 |
| ISSN: | 1882-0786 1882-0778 |
| DOI: | 10.7567/apex.11.012101 |
| Popis: | We increased the light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) by introducing a highly reflective photonic crystal (HR-PhC) into the surface of the p-AlGaN contact layer, thereby achieving a high external quantum efficiency (EQE). A low-damage HR-PhC with a lattice period of approximately 250 nm was fabricated using nanoimprinting and dry etching. A reflective Ni/Mg p-type electrode was deposited on the HR-PhC layer using a tilted-evaporation method. The EQE of a conventional DUV LED with emission around 283 nm was increased from 4.8 to 10% by introducing the HR-PhC and the reflective Ni/Mg electrode. A simple estimation of the effective reflectance of the HR-PhC p-AlGaN contact layer with the Ni/Mg electrode indicated a value exceeding 90%. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|