Electrical Properties of Selenium. II. Microcrystalline Selenium

The electrical properties of selenium have been studied in their dependence on history of preparation, i.e., as functions of temperature of initial liquid selenium, quench procedure, nucleation procedure, temperature of crystallization, and time of crystallization. The electrical properties of melt single crystals and the microcrystalline matrix of these crystals have been compared. The influence of nonmetals S, O2, I2, in small quantities on the electrical properties has been determined. Carrier densities and effective mobilities as functions of temperature of measurement have been estimated from data on thermoelectric powers and resistivities. The order of the carrier densities have been checked by measurements of the voltage dependence of capacity of completely vacuum prepared rectifiers. The frequency dependence of resistivity has been determined to gain insight into the nature of the effective mobilities.