Development of n-type Zn(O, S) buffer layer deposited by open-air CVD method for Cu(In, Ga)Se₂ solar cells

Abstract A Zn(O, S) thin-film is deposited utilizing an open-air CVD method by evaporating zinc-diethyldithiocarbamate, which a non-vacuum and dry process. In X-ray diffraction measurement, it revealed that the films have wurtzite structure [O]/([O] + [S]) ratio of 10%. bandgap energy 3.1 eV estimated from transmittance reflectance spectra. By applying as n-type buffer layer, Cu(In, Ga)Se 2 solar cells are fabricated. current density–voltage characteristics, distortion observed at bias voltages above open-circuit voltage. It implied large conduction band offset exists S)/CIGS interface. quantum efficiency spectrum in wavelength region 380–512 nm improved compared to traditional CdS layer. Finally, 9.2%-efficient CIGS cell demonstrated layer through all-dry