Optimization of Zn(O,S)/(Zn,Mg)O buffer layer in Cu(In,Ga)Se2 based photovoltaic cells

چکیده مقاله

Device modeling of CIGS based thin film solar cell with Zn(O,S)/(Zn,Mg)O buffer layer was simulated in order to find the optimum ratios of agnesium in (Zn1-x,Mgx)O and oxygen in Zn(Oy,S1-y) which led to the optimized values of x = 0.1-0.25 and y = 0.5-0.6. When the oxygen content of n(O,S) as lower than 30 %, the recombination at Zn(O,S)/CIGS interface became prominent and JSC was severely limited. It was found that the VOC is pproximately independent of magnesium content in (Zn,Mg)O and oxygen content in Zn(O,S) layers, and the efficiency is highly affected by the fill actor. Also studied were the effect of thicknesses of (Zn,Mg)O and Zn(O,S) layers while the x and y were set at x = 0.2 and y = 0.6. Our simulations how that the optimum range for thickness of the (Zn,Mg)O layer is from 70 to 100 nm, while it is 20–30 nm for the Zn(O,S) layer.