Thin film transistors (TFTs) with amorphous zinc tin oxide (ZTO) channel layer were fabricated by a simple and low-cost solution process. The ZTO thin films are highly transparent (> 90% transmittance) in the visible region. The ZTO TFTs fabricated at 400 and 500 degrees C are operated in enhancement mode. The TFT annealed at 500 degrees C shows a mobility of 14.11 cm(2) V(-1) s(-1), a threshold voltage of 1.71V, a subthreshold slope of 0.4 V dec(-1) and an on-off current ratio greater than 10(8). In addition, we investigated the gate bias stability of the TFT. Positive gate bias results in a positive shift of the threshold voltage due to the charge trapping in the channel/dielectric interface.