Analysis of electrical properties of CdSe photo-resistors in the conditions of background noise

Authors: Davydov V. N., Grebennikov A. S., Musina I. M.

Annotation: There are received the analytical expressions for photoconductivity signal and noise voltage spectral density consisting of all kinds of noise, of CdSe photo-resistor taking into account the parameters of an entrance circuit of the registration scheme when operating on the semiconductor of electric field and background noise. The results of the comparative analysis of experimental and theoretical dependences of noise show that dominating noise is the noise created by capture-emission and generation-recombination of charge carriers on localized conditions in the semiconductor band gap and connected with its structural infringements. The energy diagram of a photo-resistor is constructed. It is shown that existing physical models of photoconductivity formation well explain experimental results whereas for the explanation of noise properties of CdSe photo-resistors it is necessary to consider additional mechanisms, which change the dispersion of number of electrons and holes under the influence of bias voltage and background noise.

Keywords: cadmium selene, background noise, photoconductivity, charge fluctuations, noise minimum, capture flicker-noise on tails of conditions, superficial conditions