| 학회 | 한국재료학회 |
| 학술대회 | 2018년 가을 (11/07 ~ 11/09, 여수 디오션리조트) |
| 권호 | 24권 2호 |
| 발표분야 | G. 나노/박막 재료 분과 |
| 제목 | Properties of Nanoporous GaN double layer structures with Controlled Porosities by Combined Electrochemical and Photo-Electrochemical Etching |
| 초록 | GaN is a semiconductor with superior characteristics including wide direct band-gap, high thermal, physical, chemical stabilities and thermal conductivity[1]. These properties make GaN sutable for a wide range of applications. In recent years, nanoporous GaN material produced by electrochemical (EC) and photoelectrochemical (PEC) etching has been studied[2]. EC etching has been performed using n-type GaN where the doping concentration is an important factor in the formation of nanopores. As the doping concentration increases, the density of the nanopores increases, but the diameters of the pores decrease. PEC etching has been conducted using undoped and p-type GaN. Light with energy above the GaN bandgap plays a role in improving etching by generating electron-hole pairs. In order to achieve PEC etching, EC etching must be preceded. The hole generated by EC etching becomes a path for transferring the etchant during the PEC etching. Otherwise PEC etching non-uniformly proceeds at u-GaN. In this paper, we studied the characteristics of the porosity of GaN tuned by combined EC and PEC wet chemical etchings. Nanoporous GaN samples with varied porosities were fabricated by changing the applied voltage and etching time. The porosity was tuned by combined EC and PEC wet etching to the range 5~37%. The carrier concentration decreased in nanoporous GaN by around two orders relatively to planar GaN. The results were explained in terms of the pore size and space charge region in porous GaN. Reference [1] S. F. Chichibu, A. Uedono, T. Onuma, B. A. Haskell, A. Chakraborty, T. Koyama, P. T. Fini, S. Keller, S. P. DenBaars, J. S. Speck, U. K. Mishra, S. J. Nakamura, S. Yamaguchi, S. Kamiyama, H. Amano, I. Akasaki, Han and T. Sota , Nature Mater. , 5, 810 (2006) [2] J. D. Beach, R. T. Collins and J. A. Turner, J. Electrochem. Soc., 150, A899 (2003) |
| 저자 | 손호기1, 김규철1, 전대우2, 이인환1 |
| 소속 | 1고려대, 2한국세라믹기술원 |
| 키워드 | Electrochemical etching; Photo electrochemical etching; electrical property; nanoporous; GaN |
