Xiaojuan Fan1
Marshall University1
We report that highly transparent thin film transistors were built on glass substrates based on amorphous metal oxide and polymer hybrid structures through solution processing at room temperature. UV-Vis-NIR microscopic spectroscopy measurements were conducted on organic/inorganic hybrid materials. Thin films on Si wafers show optical interference fringes, indicating that the as-prepared samples are of high quality, i.e., smooth and uniform, from which thin film thicknesses can be derived. The transistors consist of a layer of metal oxide/PEG mixture as the active semiconductor and a layer of PMMA as dielectric materials on transparent conductive ITO contacts. Source and drain electrodes were deposited by an e-beam evaporator of 4 nm thick Cu and 200 nm thick Au in various combinations of channel length and width. The 4-probe station <i>IV</i> characteristics display a depletion mode for <i>p</i>-type transistors. Such transistors can undergo an unusual conversion from depletion mode to enhancement mode by photo-stimulation without switching the polarity of gate voltage. The mechanism is attributed to dramatic photo-current generations in amorphous metal oxide-embedded polymer hybrids under light irradiation. The selected polymers are biocompatible, enabling the fabricated transistor devices applicable to the research of neuromorphic synapses.