| 학회 | 한국재료학회 |
| 학술대회 | 2017년 봄 (05/17 ~ 05/19, 목포 현대호텔) |
| 권호 | 23권 1호 |
| 발표분야 | F. 광기능/디스플레이 재료 분과 |
| 제목 | Enhanced light output power of AlGaN-based deep ultraviolet light-emitting diodes with nano-patterned AlN/sapphire substrates |
| 초록 | AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) have attracted much attention due to their applications such as water purification and sterilization. However, the external quantum efficiency (EQE) of DUV LEDs is still much lower than that of InGaN-based visible LEDs, limiting the expansion of the applications and the market. The low EQE of DUV LEDs is attributed to poor crystal quality of the AlGaN layer, leading to low internal quantum efficiency (IQE), and low light extraction efficiency (LEE). We have investigated 280 nm AlGaN-based DUV LEDs with periodic air-voids-incorporated nanoscale patterns enabled by nanosphere lithography and epitaxial lateral overgrowth (ELO). Nanoscale ELO on the nano-patterned substrate (NPS) improved the crystal quality of overgrown layers at relatively low growth temperature of 1050 oC and at small coalescence thickness less than 2 μm. Full-width at half-maximum values of x-ray rocking curves for (002) and (102) planes of AlN were found to decrease from 235 arcsec to 186 arcsec and from 457 arcsec to 432 arcsec, respectively. In addition, the periodically embedded air-void nanostructure enhanced the LEE of DUV LEDs by breaking the total internal reflection. The light output power (LOP) of DUV LEDs on NPS was enhanced by 67% at a current of 20 mA compared to the reference DUV LEDs. We attribute such a significant enhancement of LOP to simultaneous improvements in the crystal quality of AlGaN epitaxial layer, i.e., IQE and LEE. |
| 저자 | 이동현1, 이종원2, 장정환1, 신인수1, 김로1, 박준혁2, 김종명1, 김정섭3, 이진섭3, 노혜석3, 김용일3, 박영수3, 이건도1, 박용조4, 김종규2, 윤의준1 |
| 소속 | 1서울대, 2포항공과대, 3삼성전자, 4차세대융합기술(연) |
| 키워드 | <P>III-V semiconductors; Light-emitting diodes; Ultraviolet light; Nanostructures </P> |
