In this paper, CIGS heterojunction solar cells have been proposed and
analyzed by SCAPS “Solar Cell Capacitance Simulator” the effect of
temperature and thickness on cell characteristics such as (η, FF, J
sc and V oc). The effects of various
layer parameters like thickness, carrier concentration, defect density,
mobility, and conduction band offset. The photovoltaic cell has been
studied further through capacitance-voltage simulations to obtain the
net built-in potential and the apparent doping profile. The impedance
plot (IS) analytical theory to the characterization of Cu (In, Ga) Se
2 (CIGS)-based solar cells was investigated. The
equivalent circuit of the CIGS solar cell consisting of series and
parallel resistances and a “capacitance-like element” labeled as
constant phase element (CPE) around the CdS/CIGS interface was
developed. The CPE reflects the depletion layer thickness and the p-n
interface uniformity and quality. In particular, the CPE-p-value, which
is an index of the impedance of CPE, affects the quality around the
CdS/CIGS and CIGS-Si interface in terms of defect existence and
inhomogeneity of the heterojunction. These results show a possible
candidate for the practical application of IS as a simple method for
characterizing the heterogeneity of a p-n interface.