Gasndash;surface interactions on InP monitored by changes in substrate electronic properties

摘要

The electronic properties of compensated InP crystals can be used to sensitively monitor gasndash;surface interactions. When a gas is adsorbed on these low carrier density semiconductors both the conductance and minority carrier lifetime exhibit large changes which we interpret in terms of band bending. Changes of greater than 50percnt; in the bulkhyphen;averaged conductance of Fehyphen;compensated semihyphen;insulating InP crystals have been measured for adsorption of sim;0.5 monolayers of Cl2. Using modulated NO2molecular beams the conductance changes are demonstrated to be fast (1 ms to steady state) so as to be capable of yielding quantitative rate information about the gasndash;surface interaction.