Electrical and structural properties of cadmium selenide thin film transistors

Stable thin film transistors based on cadmium senenide and silicon dioxide have been prepared. The degree of stability implies a decay of only 10% in drain current in 100 years of continuous d.c. operation. The decay is solely due to tunnelling of electrons into insulator traps and has a logarithmic time dependence. The devices have field effect mobilities up to 140 cm². Volt^?1 sec^?1, switching ratios in the range 10⁵–10⁶, and good reproducibility. The CdSe films contain the hexagonal structure and grain growth occurs during anneal. Grain size and distribution are reproducible from run to run.