Performance of top-gate thin film transistors with solution processed ZnO channel layer and PVP gate dielectric

The performance of top-gate thin film transistors with solution processed zinc oxide (ZnO) channel layer and poly(4-vinylphenol) (PVP) gate dielectric have been investigated. The transparency of the PVP film was more than 80% in the visible region, indicating that PVP can be used as a potential dielectric layer for transparent electronics. The TFTs with as-prepared ZnO as the channel layer showed a saturation field effect mobility of 6.4 x 10(-3) cm(2)/Vs with an on/off ratio of 30. The performances of the TFTs were enhanced after oxygen annealing of the ZnO channel layer prior to PVP deposition. The TFTs with 1 h oxygen annealed ZnO as the channel layer showed a saturation mobility of 0.05 cm(2)/Vs with an on/off ratio of 2.1 x 10(2). The obtained results are encouraging for fabrication of all solution processed ZnO based TFTs for cost effective technological applications. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim