Electrodeposition of Antimony Selenide Thin Films and Application in Semiconductor Sensitized Solar Cells

Sb₂Se₃ thin films are proposed as an alternative light harvester for semiconductor sensitized solar cells. An innovative electrodeposition route, based on aqueous alkaline electrolytes, is presented to obtain amorphous Sb₂Se₃. The amorphous to crystalline phase transition takes place during a soft thermal annealing in Ar atmosphere. The potential of the Sb₂Se₃ electrodeposited thin films in semiconductor sensitized solar cells is evaluated by preparing TiO₂/Sb₂Se₃/CuSCN planar heterojunction solar cells. The resulting devices generate electricity from the visible and NIR photons, exhibiting the external quantum efficiency onset close to 1050 nm. Although planar architecture is not optimized in terms of charge carrier collection, photocurrent as high as 18 mA/cm², under simulated (AM1.5G) solar light, is achieved. Furthermore, the effect of the Sb₂Se₃ thickness and microstructural properties on the photocurrent is analyzed, suggesting the hole transport is the main limiting mechanism. The present findings provide significant insights to design efficient semiconductor sensitized solar cells based on advanced architectures (e.g., nanostructured and tandem), opening wide possibilities for progresses in this emerging photovoltaics technology