Hybrid thermionic-photovoltaic converter with an In0.53Ga0.47As anode

Thermionic-photovoltaic (TIPV) converters exploit both electrons and photons emitted by a hot cathode to produce electric power. In this work, a TIPV converter structured with a tungsten cathode and an In0.53Ga0.47As photovoltaic (PV) anode (0.75 eV bandgap) is demonstrated to provide an increased output voltage with respect to the reference thermionic energy converter made of the same materials and operating under similar conditions. The higher voltage, measured to be from 0.3 to 0.5 V in the explored 1150–1450 °C temperature range, is explained by the additional contribution of the PV anode. Another work function engineered TIPV converter, obtained by coating the W cathode with LaB6 and the In0.53Ga0.47As PV anode with BaFx, has led to an output power 2 orders of magnitude higher than the uncoated TIPV converter at 1200 °C cathode temperature. This opens the route towards future optimized TIPV electrodes. •Thermionic-photovoltaic (TIPV) devices with In 0.53Ga0.47As anodes were assembled.•TIPV converter showed output voltages up to 0.5 V higher than the thermionic one.•A TIPV converter with low work function coatings (LaB6 and BaFx) was fabricated.•The coated TIPV energy converter provided an output power 100-fold than the uncoated one.