Structural and electrical properties of co-evaporated In,Garich CIGS thin films

The CIGS thin films are prepared by co-evaporation of elemental In,Ga and Se on the substrates of Mo-coated glasses at 400℃ followed by co-evaporation of elemental Cu and Se at 550℃. We study the structural and electrical properties using XRD,XRF and Hall effect measurements. In general,Cu(In,Ga)5Se8 phase exists when Cu/(In+Ga) ratio is from 0.17 to 0.27,Cu(In,Ga)3Se5 phase exists for Cu/(In+Ga) ratio between 0.27 and 0.41,Cu2(In,Ga)4Se7 and Cu(In,Ga)2Se3.5 phases exist for Cu/(In+Ga) ratio between 0.41 and 0.61,and OVC(or ODC) and CuIn0.7Ga0.3Se2 phases exist when Cu/(In+Ga) ratio is from 0.61 to 0.88. With the increase of Cu/(In+Ga) ratio,the carrier concentrations of the films gradually increase,but the electrical resistivity gradually decreases.