Characterization of photovoltaics with In2S3 nanoflakes/p-Si heterojunction

We demonstrate that heterojunction photovoltaics based on hydrothermal-grown In₂S₃ on p-Si were fabricated and characterized in the paper. An n-type In₂S₃ nanoflake-based film with unique ''cross-linked network’ structure was grown on the prepared p-type silicon substrate. It was found that the bandgap energy of such In₂S₃ film is 2.5 eV by optical absorption spectra. This unique nanostructure significantly enhances the surface area of the In₂S₃ films, leading to obtain lower reflectance spectra as the thickness of In₂S₃ film was increased. Additionally, such a nanostructure resulted in a closer spacing between the cross-linked In₂S₃ nanostructures and formed more direct conduction paths for electron transportation. Thus, the short-circuit current density (Jsc) was effectively improved by using a suitable thickness of In₂S₃. The power conversion efficiency (PCE, η) of the AZO/In₂S₃/textured p-Si heterojunction solar cell with 100-nm-thick In₂S₃ film was 2.39%.