HIGH EFFICIENCY CIGS SOLAR CELL WITH ZnxCd1-xS WINDOW LAYER

Abstract

This work conduct the numerical modeling of ZnxCd1-
xS/CIGS solar cells using the AMPS-1D software aiming to
boost the efficiency and thermal stability of the solar cells.
The substitute of typical cadmium sulfide (CdS)
window/buffer layer with ternary ZnxCd1-xS window layer
in Cu (In, Ga)Se2 (CIGS) solar cells have been analyzed by
AMPS-1D. The prospects of zinc (Zn) incorporation in CdS
as window layer for CIGS absorber layer is investigated
here. The main goal of this work is to enhance the
performance of thin film ZnxCd1-xS/CIGS solar cells with
submicron absorber, which could lead to significant
reduction of production cost and wider commercial usage.
Analysis shows that 0.5-0.6 μm CIGS absorber layer gives
good performance with suitable back surface field (BSF).
The specific BSF material selected to be investigated here is
As2Te3. The best calculated ultrathin ZnxCd1-xS/CIGS solar
cell with suggested value of ‘x’ from the simulation result
with a 100 nm of As2Te3 BSF layer should have an absorber
layer thickness of 0.6 μm (efficiency 31.096%), higher
stability in most extents, as it was found that the cells have
relatively lower negative temperature coefficient (TC)with a
TC of -0.031%/°C in the operating temperature range 45°C
to 100°C and efficiency remains almost unchanged from
25°C to 45°C.