Solution Processed AlInO/In2O3 Heterostructure Channel Thin Film Transistor with Enhanced Performance

Thin film transistors (TFTs) with solution processed AlInO/In2O3 heterostructure channels are demonstrated with enhanced performance. TFTs with single AlInO channels with various Al concentrations are used for comparison. Appropriate concentrations of Al in AlInO single layer can slightly improve the TFT performance. For the AlInO layer with Al concentration higher than 20%, the resistance is so large that no typical transfer characteristics are observed. In contrast, the overall performances are greatly improved using the AlInO/In2O3 heterostructure channel. High field effect mobility is achieved greater than 40 cm(2) V-1 s(-1) with a sub threshold slope of 0.7 V decade(-1) and on/off ratio of 10(7) from the heterostructure TFT with a AlInO (30%) top layer. The mobility is affected by the tunnel contact series resistance, which can be modulated by the thickness of the AlInO layer. The enhanced field effect mobility is attributed to the formation of 2D electron gas confined at the AlInO/In2O3 interface, which results in a bulk accumulation effect. Finally, improved positive bias stress stability is obtained by inducing the AlInO top layer with a strong Al-O bond. The as investigated results show a very promising future for oxide thin film transistor performance enhancements via heterostructure engineering.