화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Korean Journal of Materials Research, Vol.21, No.9, 491-496, September, 2011
DOI10.3740/MRSK.2011.21.9.491  Export Citation
실리콘 이종접합 태양전지 특성에 대한 Zn 도핑된 ITO 박막의 일함수 효과
Effect of Work Function of Zn-doped ITO Thin Films on Characteristics of Silicon Heterojunction Solar Cells
이승훈, 탁성주, 최수영, 김찬석, 김원목1, 김동환†
  • 고려대학교 신소재공학과
  • 1한국과학기술연구원 전자재료연구센터
Seunghun Lee, Sung Ju Tark, Suyoung Choi, Chan Seok Kim, Won Mok Kim1, and Donghwan Kim†
  • Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 137-713, Korea
  • 1Electronic materials center, Korea Institute of Science and Technology, Hawolgok-dong, Seongbuk-gu, Seoul 130-650, Korea
E-mail:
Transparent conducting oxides (TCOs) used in the antireflection layer and current spreading layer of heterojunction solar cells should have excellent optical and electrical properties. Furthermore, TCOs need a high work function over 5.2 eV to prevent the effect of emitter band-bending caused by the difference in work function between emitter and TCOs. Sn-doped In2O3 (ITO) film is a highly promising material as a TCO due to its excellent optical and electrical properties. However, ITO films have a low work function of about 4.8 eV. This low work function of ITO films leads to deterioration of the conversion efficiency of solar cells. In this work, ITO films with various Zn contents of 0, 6.9, 12.7, 28.8, and 36.6 at.% were fabricated by a co-sputtering method using ITO and AZO targets at room temperature. The optical and electrical properties of Zn-doped ITO thin films were analyzed. Then, silicon heterojunction solar cells with these films were fabricated. The 12.7 at% Zn-doped ITO films show the highest hall mobility of 35.71 cm2/Vsec. With increasing Zn content over 12.7, the hall mobility decreases. Although a small addition of Zn content increased the work function, further addition of Zn content over 12.7 at.% led to decreasing electrical properties because of the decrease in the carrier concentration and hall mobility. Silicon heterojunction solar cells with 12.7 at% Zn-doped ITO thin films showed the highest conversion efficiency of 15.8%.
Keywords:work function;heterojunction solar cell;ITO;sputter
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