Suppression of persistent effect and enhancement of photoconductivity in PbTe:CaF2 epitaxial films

• Published in: Journal of luminescence Vol. 269; p. 120499
• Main Authors: do Prado, W.P., Okazaki, A.K., Vargas, L.M.B., da Silva, M.J., de Castro, S., Rappl, P.H.O., Abramof, E., Peres, M.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2024
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2024.120499

This work presents the investigation of photoconductivity effect on CaF2 doped PbTe films, revealing a strong effect of the doping in the electrical and photoconductivity properties. For the electrical properties, Hall effect measurements were carried out under dark and illuminated conditions. We show that the photoconductivity amplitude suffers a huge increase for the doped samples at low temperatures while the persistent photoconductivity, commonly observed at room temperature for PbTe compounds, is suppressed. A simple classical Drude model for photoconductivity amplitude describes the observed effects.
•Huge photoresponse amplitude is observed in PbTe:CaF2 sample below 100 K.•The persistent effect is suppressed at low temperatures for the doped sample.•Activation energies were extracted from the photoconduction curves.•A classical model can explain the drastic increase of photoconduction.