Reduction of hysteresis in HgSe nanoparticle-based thin-film transistors using blocking oxide layers on plastics

In this study, the hysteresis mechanism is investigated for bottom-gate HgSe nanoparticle (NP)-based thin-film transistors (TFTs) using cross-linked poly vinyl alcohol (PVA) as the gate dielectric on plastics. The hysteresis loop with the clockwise direction is observed and the width of the hysteresis is reduced at long delay times. These phenomena indicate that the origin of the hysteresis is the injection of electrons from the gate electrode to the trap site located in the PVA layer. The widths of the hysteresis curves taken from the TFTs are not reduced even though the annealing treatment for the PVA gate dielectric is performed under N2, O2, and in a vacuum at 120 degrees C for 1 hour. The electron injection from the gate electrode is effectively prevented by inserting Al2O3 of 10 nm utilized as the blocking layer between gate electrode and PVA layer. The hysteresis window is remarkably reduced from about 8 V in HgSe NP-based TFTs without blocking layer to nearly 0 V in the TFTs with blocking layer of Al2O3.