Photo and thermal stability enhancement of amorphous Hf–In–Zn–O thin-film transistors by the modulation of back channel composition

The sensitivity and stability of amorphous Hf–In–Zn–O thin-film transistors with respect to visible light radiation and thermal annealing were studied. The photo and thermal stability of the devices were significantly improved by the application of a double active layer that consists of a low conductivity back channel with reduced indium content. From this double layer, significantly lower shifts in Vturn on upon illumination and thermal annealing could be achieved. However, no degradation in the field-effect mobility and reliability of the devices was observed.