TIME-RESOLVED STUDIES OF CHARGE CARRIER RELAXATION IN CHEMICALLY MODIFIED SEMICONDUCTOR ELECTRODES - N-CDSE SILANE INTERFACES

Time-resolved fluorescence is used to monitor the relaxation dynamics of minority carriers in n-type CdSe semiconductor electrodes. Five different silane compounds are used to chemically modify the interface and change the surface recombination velocity. In order to quantitate the interfacial recombination of charge carriers, a perturbative solution of a nonlinear diffusion equation is developed. These studies are combined with surface analysis and electrochemical studies to identify the nature of the chemically derivatized interface and characterize its electrical properties. This work clearly demonstrates the strong effects of surface treatment on the charge carrier dynamics and the sensitivity of fluorescence in monitoring the dynamics.