Solution-processed gadolinium doped indium-oxide thin-film transistors with oxide passivation

摘要

We studied the effect of Gd doping on the structural properties of solution processed, crystalline ln_2O_3 for thin-film transistor (TFT) application. With increasing Gd in ln_2O_3 up to 20%, the material structure changes into amorphous phase, and the oxygen vacancy concentration decreases from 15.4 to 8.4%, and M-OH bonds from 33.5 to 23.7%. The field-effect mobility for the Gd doped ln_2O_3 TFTs decreases and threshold voltage shifts to the positive voltage with increasing Gd con-centration. In addition, the stability of the solution processed TFTs can also be improved by increasing Gd concentration. As a result, the optimum Gd concentration is found to be ~5% in ln_2O_3 and the 5% Gd doped ln_2O_3 TFTs with the Y_2O_3 passivation layer exhibit the linear mobility of 9.74cm~2/Vs, the threshold voltage of -0.27 V, the subthreshold swing of 79mV/dec., and excellent bias stability.