Thin-film CdTe/CdS/ZnO solar cells and the path to affordable clean energy: Simulation-based evidence for sustainable photovoltaic design

Abstract

Global decarbonization commitments have intensified demand for low-cost, scalable solar technologies, yet the gap between laboratory-scale device physics and real-world deployment economics remains poorly addressed in simulation-oriented research. This study examines the photovoltaic performance of a CdTe/CdS/ZnO thin-film solar cell using one-dimensional numerical simulation in SCAPS-1D, focusing on two parameters with direct implications for manufacturing costs and field performance: absorber layer thickness (0.05–2 µm) and operating temperature (300–400 K). Under standard test conditions (AM1.5G, 1000 W/m², 300 K), the baseline device achieves an open-circuit voltage of 0.9482 V, a short-circuit current density of 10.43 mA/cm², a fill factor of 76.79%, and a power conversion efficiency of 7.60%. Increasing absorber thickness progressively raises both current density and open-circuit voltage through enhanced photon capture and reduced bulk recombination, while the fill factor declines owing to greater series resistance. Rising temperature degrades open-circuit voltage, fill factor, and overall efficiency - from 7.6% at 300 K to 5.7% at 400 K - primarily through an exponential increase in reverse saturation current, whereas short-circuit current density remains largely insensitive to thermal variation. At an absorber thickness of approximately 1.5–2 µm, efficiency approaches 21%, a threshold relevant to the commercial viability of CdTe modules. These findings carry concrete implications for sustainable energy deployment: reducing CdTe absorber thickness without sacrificing efficiency directly lowers material consumption and cadmium usage, easing both environmental and supply-chain concerns. The results provide simulation-based guidance for designing cost-competitive thin-film modules capable of supporting the SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action) objectives, particularly in climate-stressed regions where thermal degradation is a persistent operational challenge. Sustainable Development Goals (SDGs): SDG 7: Affordable and Clean Energy; SDG 13: Climate Action