Abstract: A radiated energy to electrical energy conversion device and technology is provided where there is a single absorber layer of semiconductor material. The thickness of the absorber layer is much less than had been appreciated as being useful heretofore in the art. Between opposing faces the layer is about ½ or less of the carrier diffusion length of the semiconductor material which is about 0.02 to 0.5 micrometers. The thickness of the absorber layer is selected for maximum electrical signal extraction efficiency and may also be selected to accommodate diffusion length damage over time by external radiation.