In collaboration with Istituto de Energia Solar (IES) of the Universidad Politecnica de Madrid (UPM), the first operational prototype of a 3-terminal hybrid thermionic-photovoltaic (TIPV) device has been developed. Thanks to the work carried out during the European project AMADEUS, we were able to successfully test the operations of the converter up to 1400 ° C in the DiaTHEMA laboratories. The device is able to convert a thermal flux into electrical energy thanks to the combined production of thermionic and photovoltaic power, i.e. the conversion of electrons and photons emitted by a high temperature cathode. In the article with Dr. Alessandro Bellucci and Prof. Alejandro Datas as corresponding authors, the fabrication, the operating principle and the first experimental demonstration of the device are reported and discussed. For the thermal photovoltaic cell, a low bandgap semiconductor (InGaAs) was used as the active material in a design specifically conceived by IES-UPM to create a grid of inverted electrodes on the back of the cell, and to keep the absorbent surface clean for the deposition of a engineered coating that functions as a thermionic collector. In addition to high temperature experiments, DiaTHEMA group developed the low work function cathode and anode coatings, with thin films of scandium oxide on the tungsten cathode and barium fluoride on the photovoltaic cell. This work represents the starting point for the development of high efficiency converters by improving both the performance of the thermionic electrodes and the design of the thermal photovoltaic cell. These devices can be used to convert active or exhausted thermal flows in various fields of application, such as industrial sites or concentrated solar power plants.
Contact: Alessandro Bellucci