ANOMALOUS TRANSIENT AND STEADY-STATE PHOTOCONDUCTIVITY STUDY IN SOME CAROTENOID POLYENES

The photoconductive properties of some carotenoid polyenes has been st udied. The growth of the photocurrent shows an overshoot in the growth -time curve before the attainment of a steady state value. From the te mperature dependence study it is observed that the steady state photoc urrent, at first increases with increase of temperature, attains a max imum at a particular temperature T-max and then decrease with temperat ure. This behaviour has been attributed to monomolecular and bimolecul ar recombination processes operative at the two temperature regimes. T he variation of photocurrent with light intensity provide information on the carrier generation processes. Both fast and slow decay of photo current have been observed at different temperatures. Temperature depe ndence of the decay constant and exponential trap distribution paramet er T-c have been evaluated.