Abstract: A spectrum-splitting concentrator photovoltaic (CPV) module utilizes direct fluid cooling of photovoltaic cells in which an array of photovoltaic cells is fully immersed in a flowing heat transfer fluid. Specifically, at least a portion of both the front face and the rear face of each photovoltaic cell comes into direct contact with heat transfer fluid, thereby enhancing coupling of waste heat out of the photovoltaic cells and into the heat transfer fluid. The CPV module is designed to maximize transmission of infrared light not absorbed by the photovoltaic cells, and therefore may be combined with a thermal receiver that captures the transmitted infrared light as part of a hybrid concentrator photovoltaic-thermal system.