Poole-Frenkel conduction in antimony-doped tin selenide thin films

Abstract

Tin selenide thin films have been prepared onto glass substrates at a temperature 240 degrees Celsius and fixed film thickness by means of a solid state reaction process at pressure about 10-5 mbar. Low level antimony doping was maintained at a concentration 1.8%. The dark current- voltage measurements have been performed on the sandwiched structures of Al-SnSe-Al and Al-SnSe:Sb-Al at temperatures in the range 143 - 300 K, and the results showed a ln J varies direct as V1/2 dependence which was indicative of the Poole-Frenkel effect. It was found that, the calculated field-lowering coefficients, (beta) p for the latter samples (3.71 - 4.81 X 10-5 eV m1/2 V-1/2) were higher than the predicted value (2.18 X 10-5 eV m1/2 V-1/2) by a factor of 1.71 - 2.21. These were further confirmed by the linear dependence of the graphs's slope and inverse of temperature. The results were explained in terms of lowering potential barrier by the interaction of electron with applied electric field.