Abstract: An X-ray spectrometer for providing imaging and energy resolution of an X-ray source comprised of a thick silicon wafer (10) having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls (16, 18) of a rectangular array of silicon X-ray detector cells (14) or "pixels". A thermally diffused aluminum electrode (20) is also formed centrally through each of the silicon cells (14) with biasing means (22, 26, 28) being connected to the aluminum cell walls (16, 18) and the centralized aluminum electrode (20) for causing lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photo-electric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging.