CuInGaSe (CIGS) based solar cells are promising, but involve costly and hazardous
and costly indium element. This work aims at solving these problems, without
sacrificing the benefits of CIGS systems. The approach is to use thinner CIGS
layers. However, very thin layers minimize absorption and lower cell performance.
Adding a second CuZnSnSe (CZTSe)-layer absorber should maintain high cell
performance. The new proposed cell that has been simulated is
MgF
2
/ZnO/Al/ZnO:i/CdS(n)/CZTSe(p)/CIGS(p)/Mo, with MgF
2 
antireflection
layer, ZnO:i passivating layer, CdS emitter layer, CZTSe/CIGS double absorber
layer, ZnO-Al transparent conductor oxide(TCO) and element almolybdenum (Mo)
back contact. A ZnO-Al film has been experimentally electrodeposited onto
FTO/Glass substrate, and then characterized. TCAD SILVACO using ATLAS
module has been used in the simulation. Various parameters, including layerthickness

and doping-concentration, are optimized, keeping smaller CIGS-layer
thickness. Band-diagrams, carrier-concentrations and current-density, in addition to
possible recombination processes, are investigated to assess performance
enhancement. The results show that increasing the one-absorber CIGS-layer
thickness by 2.5-fold, increases conversion efficiency from 22.3 to 24.3% only,
which does not justify the extra costs. Alternatively, efficiency improves from
22.40 to 29.22% by adding CZTSe to a thin 1.0 μm CIGS layer. In conclusion, the
study highlights the added value for the second-absorber layer. 

Title

Solar Energy

Publisher

Elsevier

Publisher Country

United Kingdom

Indexing

Thomson Reuters

Impact Factor

5.742

Publication Type

Both (Printed and Online)

Volume

234

Year

2022

Pages

64-80