On the mechanism of photoconductivity in polycrystalline lead selenide films
The mechanism of photoconductivity in vacuum-evaporated polycrystalline PbSe films has been studied using thermoelectric and conductivity measurements in the dark and under illumination. An analysis is made of the steady-state photoconductivity as a function of temperature and light intensity in the cases where drift and recombination are governed by the same or different barriers. It is shown that the experimental data can be interpreted by assuming a recombination barrier different from the drift barrier, the height of which is not modulated under illumination. The average recombination and drift barrier heights have been estimated to be 0.09 and 0.04 V respectively. The value of the recombination barrier trap density is found to be of the order of 1013 cm-2.