Multi‐Phase Sputtered TiO₂‐Induced Current–Voltage Distortion in Sb₂Se₃ Solar Cells

Despite the recent success of CdS/Sb2Se3 heterojunction devices, cadmium toxicity, parasitic absorption from relatively narrow CdS band gap (2.4 eV) and multiple reports inter-diffusion at interface forming Cd(S,Se) Sb2(S,Se)3 phases, present significant limitations to this device architecture. Among options for alternative partner layers in antimony chalcogenide solar cells, wide gap, non-toxic titanium dioxide (TiO2) has demonstrated most promise. It is generally accepted that anatase phase polymorphic TiO2 preferred, although there currently an absence analysis with regard influence on performance. This work approaches distinguish between phases using both surface bulk characterization methods. A fabricated a radio frequency (RF) magnetron sputtered rutile-TiO2 window layer (FTO/TiO2/Sb2Se3/P3HT/Au) achieved efficiency 6.88% near-record short–circuit current density (Jsc) 32.44 mA cm−2, which comparable established solution based fabrication methods produced highly anatase-TiO2 6.91% device. The method introduces reproducibility challenges via enhancement interfacial charge barriers multi-phase films rutile bulk. shown introduce severe S-shaped current–voltage (J–V) distortion drastic fill–factor (FF reduction these devices.