MICROWAVE MODULATED AND THERMAL MODULATED PHOTOLUMINESCENCE STUDIES OF 2H-PBI2

Lead iodide, PbI2, is a layered semiconductor. The luminescence proces ses, of 2H-PbI2 single crystals, have been examined utilizing microwav e modulated photoluminescence (MMPL) and thermal modulated photolumine scence (TMPL) spectroscopies. In the MMPL experiment, the microwave el ectric field induces a thermal heating of free carriers. The hot carri ers effect on luminescence processes is discussed. On the basis of the experimental evidence, we suggest that the hot carriers influence the luminescence processes of excitons by reducing their cross section of formation. The TMPL experiments showed that thermal modulation has cr eated a bolometric effect followed by equilibrium redistribution of ca rriers among the emitting states.