Thin films of semiconductor have been prepared on electrode surfaces by coating them with quantized colloids. The photoelectrochemical properties of semiconductor particulate films have been evaluated with both steady‐state and laser pulse excitations. The film behaves like an n‐type semiconductor with a flatband potential of −0.6 V vs.SCE. The incident‐photon conversion efficiency at 320 nm is 15%. The generation of photovoltage at these electrodes has been time‐resolved with coulostatic laser‐flash‐photolysis experiments.