KINETICS FOR ELECTRON-TRANSFER FROM LASER-PULSE-IRRADIATED COLLOIDAL SEMICONDUCTORS TO ADSORBED METHYLVIOLOGEN - DEPENDENCE OF THE QUANTUM YIELD ON INCIDENT PULSE WIDTH

The dependence of the quantum yield for reduction of adsorbed methylviologen PHI on the pulse width DELTA t and intensity of the incident laser pulse was measured on colloidal CdS stabilized with poly(acrylic acid) and on colloidal TiO//2 stabilized with poly(vinyl alcohol). The relationship among PHI , DELTA t, the laser intensity, and the rate constants for electron transfer (k//e), hole decay (k//h), and electron-hole recombination (k//r) was deduced from a quantitative reaction kinetics model. On colloidal TiO//2, differences in PHI were observed for 30-ps and 10-ns incident pulses.