Green light activated hydrogen sensing of nanocrystalline composite ZnO-In2O3 films at room temperature

The possibility of reducing the operating temperature of H 2 gas sensor based on ZnO-In 2 O 3 down to room temperature under green illumination is shown. It is found that sensitivity of ZnO-In 2 O 3 composite to H 2 nonmonotonically depends on the oxides’ content. The optimal ratio between the components is chosen. The new mechanism of nanocrystalline ZnO-In 2 O 3 sensor sensitivity to H 2 under illumination by green light is proposed. The mechanism considers the illumination turns the composite into nonequilibrium state and the photoconductivity change in the H 2 atmosphere is linked with alteration of nonequilibrium charge carriers recombination rate.