Electrical properties of electron irradiated thin polycrystalline CdSe layers

Electrical properties of nonirradiated and electron-irradiated thin layers of CdSe, sandwiched between two gold electrodes, were investigated. Thin films of CdSe, prepared by thermal-vacuum evaporation on glass substrate at a temperature of 220 degreesC, were subjected to two sessions of irradiation with 7 MeV electrons to the fluences of 2x10(15) and 4x10(15) e/cm(2), respectively. The current-voltage characteristics, recorded at temperatures in the range 150-350 K, showed that the Ohm's law is followed at low-applied voltages, in both nonirradiated and irradiated CdSe layers. In the range of high-applied voltages, the space-charge-limited current (SCLC), controlled by a Gaussian trap distribution, placed in the vicinity of the Fermi level, has been identified as the dominant conduction mechanism. An analysis in the frame of SCLC theory allowed us to obtain the parameters characterizing the trap distribution and their changes induced by electron irradiation. (C) 2001 American Institute of Physics.