| 학회 | 한국재료학회 |
| 학술대회 | 2011년 봄 (05/26 ~ 05/27, 제주 휘닉스 아일랜드) |
| 권호 | 17권 1호 |
| 발표분야 | 제 20회 신소재 심포지엄-CMPS Symposium |
| 제목 | The structural investigation for the enhancement of electrical conductivity in Ga-doped ZnO targets |
| 초록 | ZnO materials with a wide band gap of approximately 3.3 eV has been used in transparent conducting oxides (TCO) due to exhibitinga high optical transmission, but its low conductivity acts as role of a limitation for conducting applications. Recently, Ga or Al-doped ZnO (GZO, AZO) becomes transparent conducting materials because of high optical transmission and excellent conductivity. However, the fundamental mechanism underlying the improvement of electrical conductivity of the GZO is still the subject of debate. In this study, we have fully investigated the reasons of high conductivity through the characterization of plane defects, crystal orientation, doping contents, crystal structure in Zn1-xGaxO (x=0, 3, 5.1, 5.6, 6.6 wt%). We manufactured Zn1-xGaxO by sintering ZnO and Ga2O3 powers, having a theoretical density of 99.9% and homogeneous Ga-dopant distribution in ZnO grains. The GZO containing 5.6wt% Ga represents the highest electrical conductivity of 7.5×10-4Ωm. In particular, many twins and superlattices were induced by doping Ga in ZnO, revealed by X-ray diffraction measurements and TEM (transmission electron microscopy) observations. Twins developed in conventional ZnO crystal are generally formed at (110) and (112) planes, but we have observed the twins at (113) plane only, which is the first report in ZnO material. Interestingly, the superlattice structure was not observed at the grains in which twins are developed and the opposite case was true. This structural change in the GZO resulted in the difference of electrical conductivity. Enhancement of the conductivity was closely related to the extent of Ga ordering in the GZO lattice. Maximum conductivity was obtained at the GZO with a superlattice structure formed ideal ordering of Ga atoms. |
| 저자 | 윤상원1, 서종현1, 성태연2, 안재평1, 권훈3, 이건배3 |
| 소속 | 1나노재료분석센타(KIST), 2고려대, 3국민대 |
| 키워드 | Ga-doped ZnO; twin; superlattice; electrical conductivity |
