Cadmium free high efficiency Cu2ZnSn(S,Se)4 solar cell with Zn1−xSnxOy buffer layer

Abstract We have investigated the simulation approach of a one-dimensional online simulator named A Device Emulation Program and Tool ( ADEPT 2.1 ) and the device performances of a thin film solar cell based on Cu 2 ZnSn ( S,Se ) 4 ( CZTSSe ) absorber have been measured. Initiating with a thin film photovoltaic device structure consisting of n-ZnO : Al / i-ZnO / Zn 1 - x Sn x O y ( ZTO ) / CZTSSe / Mo / SLG stack, a graded space charge region ( SCR ) and an inverted surface layer ( ISL ) were inserted between the buffer and the absorber. The cadmium ( Cd ) free ZTO buffer, a competitive substitute to the CdS buffer, significantly contributes to improve the open-circuit voltage, V oc without deteriorating the short-circuit current density, J sc . The optimized solar cell performance parameters including V oc , J sc , fill factor ( FF ) , and efficiency ( η ) were calculated from the current density-voltage curve, also known as J – V characteristic curve. The FF was determined as 73.17 % , which in turns, yields a higher energy conversion efficiency of 14.09 % .