Local photocurrent detection on InAs wires by conductive AFM

Local photocurrent detection has been performed by contact mode atomic force microscopy (AFM) with a conductive tip under laser illumination on InAs wires on GaAs. We adopted a piezoresistive cantilever deflection sensor to avoid the influence of an extra laser light which is conventionally used in a cantilever deflection sensor system for AFM. In this study, we measured the photocurrent from the InAs wires on a GaAs substrate and investigated its dependences on the wavelength of an incident laser light and on bias voltage.