ELECTRICAL AND PHOTOELECTRICAL PROPERTIES OF A CHALCOPYRITE SEMICONDUCTOR AGINSE2

In this paper we report the electrical and photoelectrical properties of AgInSe2. Nyquist plots for AgInSe2, obtained at different temperatures, are perfect arcs of a semicircle with their centres lying below the abscissa at an angle alpha. Finite values of alpha (the distribution parameter) clearly indicate a multirelaxation behaviour. Transient and steady state photoconductivity of AgInSe2 has been studied at different temperatures and illumination levels. The In I(ph) vs ln F curves at different temperatures follow the empirical relation: I(ph) is-proportional-to F(gamma). Values of gamma are close to 0.5 at all the temperatures, suggesting a bimolecular recombination. Decay of the photocurrent, when the illumination is switched off, shows that during decay, photocurrent has two components, i.e. a fast decay in the beginning and a slow decay thereafter. Decay time constant for slow decay process decreases with increasing temperature, suggesting that recombination is a thermally activated process in the temperature range studied.