Effect of HRT layer and temperature in CdS/CdTe solar cells by using numerical analysis

This study utilizes the TCAD Silvaco-Atlas simulator to analyze cadmium telluride (CdTe) thin-film solar cells. The primary objective is to examine the impact of varying thicknesses of a high resistivity transparent (HRT) layer on CdTe cell efficiency. It compares the efficacy of undoped Tin or Zinc-Oxide (i-SnO
2
or i-ZnO) as the HRT layer and investigates the influence of temperature on cell performance within the range of 270 K to 340 K. Simulation outcomes reveal that the HRT layer thickness has minimal effect on cell efficiency, suggesting that a thickness of 20 nm is optimal. Moreover, i-SnO
2
demonstrates superior efficiency compared to the i-ZnO layer. The optimized design, FTO/i-SnO
2
/CdS/CdTe/Cu
2
O, achieves a conversion efficiency of 24.47% (open-circuit voltage: 1.03 V, short-circuit current density: 27.70 mA/cm
²
, fill-factor: 85.90%), under the AM1.5 global spectrum and at an operating temperature of 300 K. Additionally, it is noted that efficiency decreases linearly with rising temperature, yet efficiencies exceeding 26.5% can be attained in CdTe solar cells at a temperature of 270 K.