PHOTOCONDUCTIVITY KINETICS IN PB1-XMNXTE(IN) SOLID-SOLUTIONS WITH VARYING COMPOSITION

The photoconductivity kinetics of single crystal solid solutions of Pb 1-xMnxTe(In) (x less than or equal to 0.1) with a stabilized Fermi lev el position are studied under illumination at temperatures of 4-35 K. It is found that changing the composition of the solid solution leads to a qualitative change in the photoconductivity kinetics and to the a ppearance, as x is increased, of a segment in the kinetic curves with comparatively fast relaxation, along with a delayed photoconductivity. The fraction of rapidly relaxing carriers increases as x is raised. T he experimental data are analyzed using a configuration diagram which assumes the existence of a metastable state, in addition to the ground state, of the impurity center. It is shown that, assuming a linear di splacement of the impurity energy levels, a fast relaxation process ca n be observed in solid solutions where the metastable level falls in t he forbidden band. (C) 1996 American Institute of Physics.