= 아 래 =
1. 일 시 : 2013. 6. 4 (화), 16:00 ~
2. 장 소 : 응용공학동 1층 영상강의실
3. 연 사 : 곽지혜 박사 (한국에너지기술연구원 태양에너지연구단)
4. 제 목 : CZTS-based compound thin film solar cells
Cu2ZnSnSe4 (CZTSe) or Cu2ZnSnS4 (CZTS) compound semiconductor is currently being investigated as an indium-free alternative to the CIGS absorber layer in thin film solar cells, and many notable research results have been reported. The best solar cell device has shown maximum conversion efficiency of 11.1% based on Cu2ZnSn(S,Se)4 (CZTSSe) prepared using the hydrazine-solution process by IBM. Based on sputtering process, the solar cells produced about 6.77% and 7.75% efficiencies with CZTS and CZTSSe absorber layers, respectively, prepared by sulfurization after sputtering. Although co-evaporation technique seems one of the best methods to control the film composition, only limited studies have been done on thin film solar cells based on CZTSe deposited by co-evaporation process. Solar Frontier and IBM also produced over 8% efficiency of solar cells with CZTS and CZTSe absorbers, respectively, based on the evaporation process, but it was by two-step process involving co-evaporated precursor preparation followed by a separate annealing step of sulfurization and selenization, respectively, which is not carried out in a chamber. CZTSe absorber layers were prepared by co-evaporation processes without any post-annealing. As-deposited thin films were characterized and the best sample produced 6.14% of conversion efficiency after fabrication of the solar cell (active area 0.455 cm2, without anti-reflection coating, Voc = 0.326 V, Jsc = 32.217 mA/cm2, F.F. = 58.45%).