Electrical, optical and photoconductive properties of Sn-doped indium sulfofluoride thin films

• Autor(a) principal: Vygranenko, Yuri
• Data de Publicação: 2021
• Outros Autores: Fernandes, M., Vieira, Manuela, Lavareda, G., Carvalho, C. Nunes De, Brogueira, P., Amaral, A., Barradas, N. P., Alves, E.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/12547
• topic: Indium sulfofluoride; Thin-films; Amorphous semiconductors; Optical properties; Photoconductivity; Photovoltaics

This work reports on undoped and Sn-doped indium sulfofluoride thin-films deposited by radio-frequency plasma-enhanced reactive thermal evaporation. The deposition was performed evaporating pure indium or indium-tin alloy in SF6 plasma at substrate temperatures ranging from 373 to 423 K. Rutherford backscattering analysis and secondary-ion mass spectrometry were used to determine the chemical composition of the films. The film characterization includes electrical, optical, and photoconductivity measurements. The resistivity of undoped material varies in a wide range of 1 G Omega-cm to 2 T Omega-cm depending on deposition conditions. Sn doping leads to a decrease in the resistance down to 8 M Omega-cm. The films are highly transparent in the visible-infrared region due to an indirect bandgap of 2.7-3 eV. Moreover, the doped material is highly photosensitive in the blue -UV region. Photoconductivity kinetics under various excitation conditions was also studied. The synthesized material is a promising candidate for a buffer layer in chalcogenide-based solar cells.