A radiation detector (100) includes a photovoltaic layer (102) with first and second opposing sides. The photovoltaic layer is configured to absorb first radiation at the first side and produce electrical charge. The detector further includes a porous silicon quantum dot layer (104) disposed at the second side of the photovoltaic layer and configured to receive second radiation and convert the received second radiation into an electrical signal indicative of an energy level of the received second radiation. The detector further includes an acquisition and communication layer (106) disposed adjacent to the porous silicon quantum dot layer and configured to receive the electrical signal and transmit the electrical signal to a device remote from the radiation detector. The detector further includes an energy storage layer (108) disposed adjacent to the acquisition and communication layer and configured to store the electrical charge and supply the stored electrical charge as operating power to the acquisition and communication layer.