Thin-film transistors (TFTs) with multistacked active layers (MSALs) have been studied to improve their electrical performance. The performance enhancement with MSALs has been attributed to higher film density in the effective channel; the density was higher because the porosities of the sublayers were reduced by filling with solution. The proposed TFT with MSALs exhibited an enhanced field-effect mobility of 2.17 cm(2)/(V s) and a threshold voltage shift under positive bias stress of 8.2 V, compared to 1.21 cm(2)/(V s) and 18.1 V, respectively, for the single active layer TFT.

To enhance the solution-processed thin-film transistor (TFT) performance, we proposed a TFT with self-passivated multistacked active layers (SP-MSALs). This structure exhibited self-protection in the active layer as compared with the conventional TFT structure. The self-passivation layer prevented the leakage current path at the back-channel region, thus improving the field-effect mobility (μFET) and the positive bias stress (PBS) reliability. In addition, it was very stable in the exposed environment even for 150 h. As a result, the proposed SP-MSAL TFT caused the threshold voltage shift (ΔVTH) under PBS to improve from 8.2 to 4.2 V as compared with the conventional MSAL TFTs.