Wide-gap CIGS solar cells with Zn 1-y Mg y O transparent conducting film

Zn 1-y Mg y O bandgap controllable transparent conducting films were used for the wide-gap Cu(In 1-x Ga x )Se 2 thin film solar cells. Undoped Zn 1-y Mg y O and Al doped Zn 1-y Mg y O films were deposited by co-sputtering using a carousel type sputtering apparatus. Zn 1-y Mg y O films with Mg content y of up to 0.10 were examined. For Cu(In 1-x Ga x )Se 2 with band gap energy ˜1.38 eV, the cell performance was slightly improved by using Zn 1-y Mg y O and Al doped Zn 1-y Mg y O instead of ZnO and Al doped ZnO. An unexpected improvement of short circuit current density was observed.