Active layer thickness effects on the structural and electrical properties of p-type Cu2O thin-film transistors

The authors investigated the effects of active layer thickness on the structual, optical, and electrical characteristics of p-type Cu2O thin-film transistors (TFTs). It was observed that as the channel thickness increases, the average grain size and root mean square roughness of the Cu2O thin films increase, but the optical transmittance notably decreases, especially in the short wavelength range below 500 nm. The p-type Cu2O TFT device exhibits the cleanest transfer function with only a small subthreshold slope when the channel thickness is 45 nm, whereas notable subthreshold slope humps are observed in the transfer curves for devices with thicker channels.