Abstract: To know well the effect of Cu concentration on the performance of of Cu2ZnSnSe4 (CZTSe) thin film solar cells.CZTSe thin film solar cells prepared at different Cu evaporation temperature was investigated.The results indicate that the low TCu(1400 ℃) cause additional reflections of secondary phase SnSe and the films are N-type conduction.The quality of crystallization of CZTSe films is improved with increasing TCu.But the secondary phase of CuxSey is observed for CZTSe films deposited at TCu of 1500 ℃.Both secondary phase of SnSe and CuxSey could cause devices electrically inactive.The best solar cell with an efficiency of 2.63; is obtained at medium TCu of 1450 ℃ (active area 0.34 cm2).

Key words: To know well the effect of Cu concentration on the performance of of Cu2ZnSnSe4 (CZTSe) thin film solar cells.CZTSe thin film solar cells prepared at different Cu evaporation temperature was investigated.The results indicate that the low TCu(1400 ℃) cause additional reflections of secondary phase SnSe and the films are N-type conduction.The quality of crystallization of CZTSe films is improved with increasing TCu.But the secondary phase of CuxSey is observed for CZTSe films deposited at TCu of 1500 ℃.Both secondary phase of SnSe and CuxSey could cause devices electrically inactive.The best solar cell with an efficiency of 2.63; is obtained at medium TCu of 1450 ℃ (active area 0.34 cm2).