On the Stability of Operation of Antimony Sulfide Selenide Thin Film Solar Cells Under Solar Radiation

Operational stability of FTO/CdS/Sb 2 S 1.08 Se 1.92 /C‐Ag thin film solar cells under solar radiation is presented. These solar cells are produced on fluorine‐doped SnO 2 (FTO) by thermal evaporation of Sb 2 S 3 and Sb 2 Se 3 powders. Thin film of Sb 2 S 1.08 Se 1.92 (300 nm) shows a bandgap of 1.45 eV. Its electrical conductivity is 10 −7  Ω −1  cm −1 (dark) and 10 −5  Ω −1  cm −1 under illumination. Thin film of CdS (120 nm) for the solar cell is obtained on FTO by chemical deposition. Antimony chalcogenide film is deposited on FTO/CdS substrates maintained at 425 °C via thermal evaporation from a mixture of Sb 2 S 3 and Sb 2 Se 3 powders. Subsequently, graphite paint and silver paint electrodes of area 0.49–0.64 cm 2 are applied on it. Efficiency of conversion ( η ) is 5.9 % for the best solar cell and 5.6% on an average for eight cells. Open circuit voltage ( V oc ) of the cell is 0.453 V; short circuit current density ( J sc ), 24.7 mA cm −2 ; and fill factor, 0.53. For solar cells placed under the sun over 5 days in the exterior with exposure of 24 kWh m −2 , η dropped to 5%. Under 30 suns, V oc of 0.54 V and J sc of 130 mA cm −2 are recorded. The cells remained functional.