Erbium doped amorphous silicon has been prepared by the evaporation of Er containing metallo-organics inside the plasma of a plasma enhanced chemical vapor deposition (PECVD) system. The samples combine photoluminescence efficiency and photo sensitivity at room temperature. The spatial distribution of Er was found to be inhomogeneous due to insufficient control of the Er source. Electron and hole transport properties as well as defect properties were measured by means of steady-state photocurrent, constant photocurrent method (CPM), modulated photocurrent (MPC) and steady-state photocarrier grating (SSPG) experiments, which are interpreted on the basis of the inhomogeneous distribution of Er over the film thickness. (C) 2000 Elsevier Science B.V. All rights reserved.