| 학회 | 한국재료학회 |
| 학술대회 | 2007년 봄 (05/10 ~ 05/11, 무주리조트) |
| 권호 | 13권 1호 |
| 발표분야 | 반도체재료 |
| 제목 | Well protection layer as a novel pathway to increase indium composition: a route towards green emission from blue InGaN/GaN multiple quantum well |
| 초록 | In an effort to find a novel route towards green emission from blue InGaN/GaN multiple quantum well (MQW), we introduced a well protection layer (WPL) and examined its effects on the optical properties of the MQW. The 5-pair MQW, consisting of InGaN well grown at 750 oC and GaN barrier grown at 850 oC, was simply embedded by metalorganic vapor phase deposition between p- and n-GaN cladding layer on sapphire(0001) substrate. While this two-temperature MQW growth scheme seemed better suited to the GaN barrier quality, it exposed the volatile InGaN well to a higher temperature ambient upon ramping-up process to grow the barrier. In order to prevent the fragile well, a thin GaN WPL was coated subsequently on each well layer at the same temperature before the temperature ramping-up. Consequently, it was found that the WPL directly influenced indium composition and optical properties of the MQW. Indium composition was in fact increased, as was evident from x-ray diffraction experiments. In addition, photoluminescence measurements showed emission peak wavelength was increased from 464 nm to 520 nm. Furthermore, to increase indium composition starting from a blue MQW, various InGaN well growth schemes (such as increased flow rate of indium precursor and decreased growth temperature) were explored and compared with each other. These results provide the proof evidence that the WPL effectively suppresses indium re-evaporation during the ramping-up time. Present study proposes that the WPL paves a new pathway to increase the wavelength of InGaN/GaN MQW. |
| 저자 | Jin-Woo Ju1, Lee-Woon Jang2, Hwa-Soo Kim1, Haeng-Keun Ahn2, In-Hwan Lee1 |
| 소속 | 1School of Advanced Materials Engineering and Research Institute of Advanced Materials Development, 2Chonbuk National Univ. |
| 키워드 | well protection layer; InGaN/GaN; MQW; MOCVD; Green LED |
