A study will be made of the physics of solid surfaces and interfaces which possess unique bonding configurations and electronic properties. A combination of surface sensitive techniques, including photoemission, inverse photoemission and optical properties will be used to probe the kinetics of interface formation, the nature of bonding between different materials and the atomic and electronic structure of interfaces between semiconductors, metals and insulators. A novel photothermal displacement spectroscopy will be employed to obtain information not accessible with electron spectroscopies. This work is of importance for the microelectronics industry.