NOVELTY - The assembly has an inorganic semiconducting material host matrix defining a surface and another surface and thickness between the surfaces. A set of nanoparticles is interspersed within thickness of the host matrix and in combination with the host matrix generates a charge carrier upon interaction with the radiation. An electrode (2) is placed adjacent to the former surface of the host matrix. Another electrode is placed adjacent to the latter surface of the host matrix, where the generated electricity is output from the electrodes.    USE - Assembly for converting radiation e.g. infrared, visible light, UV light, x-ray, gamma ray, beta ray, cosmic ray and geothermal radiations (all claimed), from ambient thermal energy e.g. geothermal energy conversion device deriving energy from earth, geothermal energy in earth and infrared energy, to direct current (DC) electricity for measuring amount of incident radiation in photovoltaic nuclear/atomic battery devices. Uses include but are not limited to spacecrafts, portable devices, sensors and solar cells in solar panels.    ADVANTAGE - The host matrix utilizes additive materials such as hydrogen, helium, lithium and boron so as to improve sensitivity and expand selection of types of radiation. The assembly utilizes quantum dot materials with a high atomic number so as to increase stopping power of radioactive particles and interaction of the particles with active volume of the devices. The assembly enables usage of a wider range of radioisotopes and captures a large amount of energy derived from the radioisotopes, thus resulting in better power output for devices, and hence improving conversion efficiency to use nuclear batteries in wide range of applications.    DETAILED DESCRIPTION - The host matrix includes a portion made of porous silicon (4).    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an energy conversion device to provide a nuclear battery.    Electrode (2)    Porous silicon (4)    Quantum dots (6)    Energy conversion device (100)