SIMULATION OF CZTS/ZnO/FTO HETERO-JUNCTION SOLAR CELL

Abstract

The abundance of Copper, Zinc, Tin and Sulphur is the reason that CZTS is a probable material for large-scale power generation. The environmentally friendly nature of CZTS when paired with either Zinc Oxide (ZnO) or Fluorine doped Tin Oxide (FTO), which is also abundant and non-toxic has made it choice material for investigation that could produce a p-n hetero-junction desired in changing solar energy into electricity. Solar cell Capacitance simulator (SCAPS 1-D), developed by Dr. Marc Burgelman and his research group at University of Gents, Belgium, is the simulator tool employed to model the desired p-n hetero-junction solar cell. SCAPS-1D was used to solve the Poisson, hole and electron continuity equations so that information concerning the device properties of the CZTS/ZnO/FTO based solar cells could be obtained. The Solar cell data were then processed to obtain I-V measurements. The values of band offsets at the ZnO/FTO interface were found to be 0.135 eV and 0.384 eV and at CZTS/ZnO were 0.226 eV and 2.008 eV respectively. It had been shown from the results thata solar cell with CZTS/ZnO/FTO hetero-junction layer with efficiency of 24.23 % is realistic andit is of the order of the most efficient thin film solar cell produced with Cu(In,Ga)Se2 (CIGS) and Cadmium Sulfide (CdS) based ones. This implies that CZTS can favourably compete as an efficient absorber layer. The planar configuration proposed in this work was to enable the simulation with SCAPS.