Abstract

When simple molecules adsorbed on clean crystals surfaces interact with light dynamical studies can reveal a great deal about the photophysics of absorption, energy relaxation, and stimulated desorption, as well as the dynamics of photochemical reactions.¹ In typical photochemical etching and deposition systems, however, surfaces are usually rough and disordered, and reactions involve a wide range of adsorbates which can undergo both photochemical and spontaneous processes. Although this level of complexity would seem to preclude obtaining as detailed a picture as is possible for the methyl halides, for example, rather simple experiments can provide direct and indirect information on important surface photoprocesses. In this talk early efforts to understand microscopic aspects of two very different photochemical systems will be described, with a particular focus on data pertaining to the influence of electronic excitation on adsorption of reactants and desorption of products.

© 1989 Optical Society of America