Enhanced solar cell efficiency: copper zinc tin sulfide absorber thickness and defect density analysis

• K. C. Devendra, 
• Deb Kumar Shah, 
• Subhash Kumar, 
• Nawraj Bhattarai, 
• Dipak Raj Adhikari, 
• Khim B. Khattri, 
• M. Shaheer Akhtar, 
• Ahmad Umar, 
• Ahmed A. Ibrahim, 
• Mohsen A. M. Alhamami, 
• Sotirios Baskoutas & 
• O.-Bong Yang 

Journal of Materials Science: Materials in Electronics volume 34, Article number: 1699 (2023) 

Cite this article

Devendra, K.C., Shah, D.K., Kumar, S. et al. Enhanced solar cell efficiency: copper zinc tin sulfide absorber thickness and defect density analysis. J Mater Sci: Mater Electron 34, 1699 (2023). https://doi.org/10.1007/s10854-023-11125-y

Abstract

Copper zinc tin sulfide solar cell (CZTS), Cu2ZnSnS4-based solar cells have shown promising conversion efficiency because of their ease of variation in configurations. In this work, the architecture of a ZnO–Al/i–ZnO/n–CdS/CZTS/Mo solar cell was optimized by using Silvaco Atlas simulation software. In this simulation study, the thickness and defect density of the CZTS layer has been varied to achieve the highest efficiency of 26.58%, with Isc = 36.64 A and Voc = 0.909 V at a defect density of 1.8 × 1012 cm−3. Increase in the layer thickness of CZTS improves the photon absorption and cell efficiency. This study has evidenced the impact of defect density on the absorber layer, including photo-generation rate, recombination rate, and solar cell efficiency. By optimizing the device parameters, it has achieved a fill factor of 79.74% under AM 1.5 illumination, demonstrating the potential for low-cost, highly efficient CZTS solar cells.

 

Numerical assessment of optoelectrical properties of ZnSe–CdSe solar cell-based with ZnO antireflection coating layer

Authors: 

D. Parajuli, 

Devendra KC, 

Khim B. Khattri, 

Dipak Raj Adhikari, 

Raid Anam Gaib & 

Deb Kumar Shah 

Scientific Reports volume 13, Article number: 12193 (2023) 

Cite this article

Parajuli, D., KC, D., Khattri, K.B. et al. Numerical assessment of optoelectrical properties of ZnSe–CdSe solar cell-based with ZnO antireflection coating layer. Sci Rep 13, 12193 (2023). https://doi.org/10.1038/s41598-023-38906-z

Abstract:

In this work, a numerical assessment of the optoelectrical properties of the ZnO–ZnSe–CdSe heterojunction for a thin and cost-effective solar cell was made by using the PC1D simulation software. The photovoltaic (PV) properties have been optimized by varying thicknesses of the absorber layer of the p-CdSe layer, the window layer of n-ZnSe, and the antireflection coating (ARC) layer of ZnO, a transparent conductive oxide with enhanced light trapping, and wide bandgap engineering. There is a positive conduction band offset (CBO) of ΔEc = 0.25 eV and a negative valence band offset (VBO) of ΔEv = 1.2 − 2.16 =  − 0.96 eV. The positive CBO prevents the flow of electrons from the CdSe to the ZnSe layer. Further, the impact of doping concentration on the performance of solar cells has been analyzed. The simulation results reveal the increase in the efficiency of solar cells by adding an ARC. The rapid and sharp increase in the efficiency with the thickness of the window layer beyond 80 nm is interesting, unusual, and unconventional due to the combined effect of morphology and electronics on a macro-to-micro scale. The thin-film solar cell with the structure of ZnO/ZnSe/CdSe exhibited a high efficiency of 11.98% with short-circuit current (Isc) = 1.72 A, open-circuit voltage (Voc) = 0.81 V and fill factor (FF) = 90.8% at an optimized thickness of 2 μm absorber layer, 50 nm window layer, and 78 nm ARC layer. The EQE of solar cells has been observed at about 90% at a particular wavelength at 470 nm (visible light range). Around 12% of efficiency from such a thin-layered solar cell is highly applicable.