Photocurrent measurements for laterally resolved interface characterization

A miniaturized optical set-up based on a CDROM player optic was developed f or LAPS (light addressable potentiometric sensors). A focus of 2.6 mu m was achieved using this easy to handle device. The lateral resolution of LAPS measurements can be improved by using GaAs as the semiconductor material in stead of Si. The diffusion length of the minority charge carriers was deter mined to be smaller than 3.1 mu m. A new method called SPIM (scanning photo -induced impedance microscopy) is described. Using this technique, the impe dance of thin films can be measured with lateral resolution.