锌蒸发温度对共蒸发法制备Cu_2ZnSnSe_4太阳电池性能的影响

Influence of zinc evaporation temperature on the performance of Cu_2ZnSnSe_4 thin film solar cells fabricated by co-evaporation process

由于Zn元素的含量对Cu_2ZnSnSe_4(CZTSe)化合物太阳电池的性能有重要的影响,本文主要研究了不同锌蒸发温度对CZTSe太阳电池性能的影响。研究表明:当锌元素蒸发温较低时,CZTSe薄膜中的铜元素过量会使电池失效;而当锌元素蒸发温度较高时,CZTSe薄膜中的锌元素过量,该条件下制备的电池具有高的开路电压但短路电流密度较低,这可能是由于晶界处的硒化锌减少了载流子复合,但表面的硒化锌却阻碍了载流子的输运。通过优化锌的蒸发温度,在较合适的480℃锌蒸发温度条件下制备出效率为1.40%(有效面积0.34cm^2)的CZTSe太阳电池。

To know well the effect of Zn concentration on the performance of Cu2 ZnSnSe4 （CZTSe） thin film solar cells, CZTSe thin＂ fthn solar cells prepared at different Zn evaporation temperature was investigated. The results indicated that the low TZn （460℃） caused devices with excess copper to be electrically inactive. On the contrary, the high TZn the Zn excess was less harmful to device performance with a higher Vcc but a lower Jsc. The reason might be that ZnSe phase could reduce the recombi- nation near the grain boundary but result in a current blocking behavior at the absorber surface. The best solar cell with an effi- ciency of 1.40% was obtained at medium Tzn of 480 ℃ （active area 0. 34 cm^2）.