Chemical Bath Deposition of Undoped and Bi-doped n-Cu2Se Films and their Optoelectrical Properties

Introduction: The effluence of Bi3+ doping on the microstructure and property of the undoped and Bi3+-doped Cu2Se films deposited by chemical bath deposition were studied. Methods: The films showed average UV-visible transmittances of ~73.29-84.10 % that increased with increasing Bi3+ content. The optical bandgaps calculated from optical spectra increased with increasing Bi3+ content. Strong bandgap emission at ~629 nm was also observed. Moreover, the films had actual Se/Cu<2 and n-type conductive. Result: The sheet resistance of ~4.13-96.440-3 Ω·cm first decreased and then increased with the increase in Bi content. Conclusion: Various optical constants of the films were estimated with the UV-visible light spectra.