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 degrees 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 degrees C cathode temperature. This opens the route towards future optimized TIPV electrodes.