Antimony sulfide selenide thin film solar cells with comparable characteristics prepared via a choice of chemical deposition or vacuum thermal evaporation

Abstract

Antimony sulfide selenide solar cells, FTO/CdS/Sb₂S_x1Se_3-x1/Sb₂S_x2Se_3-x2/graphite-Ag, of above 5 % conversion efficiency (η), open circuit voltage (V_OC) 0.45 V and short circuit current density (J_SC) 24 mA cm ^{– 2}, were obtained for Sb₂S_xSe_3-x (160–350 nm) of variable bandgap (E_g) 1.25–1.5 eV prepared by chemical deposition (CD) or thermal evaporation (TE). Commercial SnO₂:F (FTO) was coated first with a CdS thin film. For CD - Sb₂S_xSe_3-x absorbers, selenosulfate and thioacetamide were at a molar ratio 0.1:3 for the first deposition, and 1:3 in the second deposition (film thickness, 160 nm). In TE, Sb₂Se₃-Sb₂S₃ was in 1:3 ratio in the first crucible, and distinct in the second (film thickness, 300 nm). CD-Solar cells had η, 5.2 %, J_SC 23.6 mA cm ^{– 2} and V_OC of 0.41 V and the TE-solar cells, 5.75 %, 24.5 mA cm ^{– 2} and 0.45 V, respectively. Thus, Sb₂S_xSe_3-x of variable E_g provides a higher V_OC and conserves J_SC.