Tunable Performance of P-Type Cu$_{2}$O/SnO Bilayer Thin Film Transistors

Novel tunable p-type thin film transistors (TFTs) were developed by adopting Cu2O/SnO bilayer channel scheme. Using Cu2O film produced at a relative oxygen partial pressure Opp of 10% - as an upper layer - and 3% Opp SnO films - as lower layers - we built a matrix of bottom gate Cu2O/SnO bilayer TFTs with different thicknesses. We found that the thickness of the Cu2O layer plays a major role in the oxidization process exerted onto the SnO layer underneath. The thicker the Cu2O layer the more the underlying SnO layer is oxidized, and hence, the more the transistor mobility is enhanced at a certain temperature. Both the device performance and the required annealing temperature could then be tuned by controlling the thickness of each layer of the Cu2O/SnO bilayer TFT.