Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
Contact potential difference measurements of synchrotron radiation-induced surface photovoltage (SPV) are performed on GaAs(110) as a function of metal coverage and temperature. On low doped n-samples, the low temperature SPV (0.55 eV) is almost equal to the total band bending at submonolayer coverage and discharges with a time constant of hours. Above a monolayer, the rate of discharging increases dramatically, emphasizing the role of charge leakage through the overlayer. The room temperature SPV is considerably smaller (0.2 eV) and its coverage dependence does not correlate with that of band bending. A metal-dependent enhancement of SPV is found. No significant SPV is detected on highly doped p-GaAs.