Eur. Phys. J. Appl. Phys. 89, 10302 (2020)
https://doi.org/10.1051/epjap/2020190265

Regular Article

Photoconductivity kinetics of indium sulfofluoride thin films^★

¹ CTS-UNINOVA, Quinta da Torre, 2829-516 Caparica, Portugal
² Departamento de Engenharia Electrónica e Telecomunicações e de Computadores, ISEL, Lisboa, Portugal
³ Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Liston, Portugal
⁴ CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Liston, Portugal
⁵ Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Liston, Portugal

^* e-mail: yvygranenko@deetc.isel.ipl.pt

Received: 2 September 2019
Received in final form: 2 December 2019
Accepted: 17 February 2020
Published online: 1 April 2020

Abstract

Indium sulfofluoride is an amorphous wide-gap semiconductor exhibiting high sensitivity to UV radiation. This work reports on the kinetics of photoconductivity in indium sulfofluoride thin films along with their electrical and optical properties. The films were deposited by radio-frequency plasma-enhanced reactive thermal evaporation. The film characterization includes electrical, optical, and photoconductivity measurements. The films are highly transparent in the visible-infrared range due to an indirect bandgap of 2.8 eV. The spectral response measurements have revealed existence of the band tail states. The synthesized compound is highly resistive (∼200 MΩ-cm at 300 K) and exhibits extremely slow photocurrent relaxations. Photoconductivity kinetics was studied under various excitation conditions. A dependence of the photocurrent on the incident photon flux was also determined.