Enhanced Electrical Performance and Bias‐Stress Stability of Solution‐Processed Bilayer Metal Oxide Thin Film Transistors

Herein, solution-processed indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) with a bilayer structure are investigated by embedding an ultrathin layer of indium zinc oxide (IZO) between the gate dielectric and IGZO film. The optimized IGZO/IZO bilayer TFTs exhibit a high field-effect mobility (mu(FE)) of 8.3 cm(2 ) V-1 s(-1), and the bias-stress stability of the bilayer TFTs is greatly improved compared with that of the single-layer IGZO devices. In addition, temperature-dependent mobility and V-T are investigated to reveal the trap distribution in the bilayer IGZO/IZO and single-layer IGZO TFTs. Moreover, low-voltage bilayer TFTs with a high mobility of 10.4 cm(2 ) V-1 s(-1) are demonstrated.