ZnxCd1 − xS as a heterojunction partner for CuIn1 − xGaxS2 thin film solar cells

Zinc cadmium sulfide (ZnxCd1 − xS) heterojunction partner layer prepared with chemical bath deposition (CBD) has exhibited better blue photon response and higher current densities due to its higher bandgap than that of conventional cadmium sulfide (CdS) layer for CuIn1 − xGaxS2 (CIGS2) solar cells. CIGS2/ZnxCd1 − xS devices have also shown higher open circuit voltage, Voc indicating improved junction properties. A conduction band offset has been observed by J–V curves at various temperatures indicating that still higher Voc can be obtained by optimizing the conduction band offset. This contribution discusses the effect of variation of parameters such as concentration of compounds, pH of solution and deposition time during CBD on device properties and composition and crystallinity of film. Efficiencies comparable to CIGS2/CdS devices have been achieved for CIGS2/ZnxCd1 − xS devices.