High efficiency Cu 2 ZnSnS 4 solar cells have been fabricated on glass substrates by
thermal evaporation of Cu, Zn, Sn, and S. Solar cells with up to 6.8% efficiency were
obtained with absorber layer thicknesses less than 1 μ m and annealing times in the
minutes. Detailed electrical analysis of the devices indicate that the performance of the
devices is limited by high series resistance, a “double diode” behavior of the current voltage
characteristics, and an open circuit voltage that is limited by a carrier recombination process …