TITLE:
Enhancing Strategy of CIGS-Based Thin-Film Solar Cells Performances by Optimizing the Transparent Conductive Oxide (TCO) Layer
AUTHORS:
Adama Zongo, Soumaïla Ouédraogo, Boureima Traoré, Issiaka Sankara, Marcel Bawindsom Kébré, François Zougmoré, Zacharie Koalga, Frédéric Ouattara
KEYWORDS:
Numerical Simulation, CdS/TCO Interface, Interface Defects, Conduction Band Offset, Transparent Conductive Oxide
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.16 No.5,
May
26,
2026
ABSTRACT: In this paper, based on numerical simulation, we use SCAPS-1D software to analyze the electrical and optical properties of the transparent conductive oxide (TCO) layer and the interface between the TCO layer and the CdS buffer layer on the performance of the CIGS solar cell. To achieve our purpose, we studied the important parameters of the TCO layer, such as its thickness and doping. For the TCO/CdS interface, we analyzed the impact of the conduction band offset (CBO) due to the band alignment. Numerical simulation results show that the thickness and doping of the TCO layer are crucial parameters for optimizing the electrical and optical parameters of CIGS-based solar cells. The optimal values for the electrical (open-circuit voltage, current density, fill factor and efficiency) and optical (quantum efficiency) parameters are obtained when the TCO layer thickness is in the range 0.025 and 0.035 μm, and the doping in the order of 1015 cm?3. The study of band alignment at the TCO/CdS interface has shown that strong negative conduction band offset (cliff) or strong positive conduction band offset (peak) favors recombination at this interface. Very good performances are obtained for a conduction band offset at the CdS/ZnO interface of no more than ?0.3 eV (CBO(CdS/ZnO) ≈ ?0.3 eV).