Improvement the Efficiency of CIGS Thin Film Solar Cells by Changing the Doping of the Absorbent Layer and Adding the InAsP Layer

In this article, the functionality of solar cells structure based on CuIn1xGaxSe2 is investigated. This type of solar cell consists of different layers, namely ZnO (TCO layer), Cd_S (Buffer layer), CIGS (Absorbent layer), and MO (Substrate layer). Two layers, Cd_S and CIGS, form a PN Junction.  CIGS Thin Film Solar Cell is simulated using SILVACO software. The absorbent layer doping was originally changed.  Later doping was kept constant and Ptype layer of InAsP was added. Their effect on cell function was observed and examined. It was observed that after doping some parameters of the solar cell have improved whilst some others had decreased. It was also concluded that examined increase of decrease in the amount of dopant would reduce our efficiencies of solar cell.  Added the InAsP layer leads to increased open circuit voltage, short circuit current and the solar cell power, consequently gives the yields about 33.2%, which is acceptable efficiency.