| Summary: | 博士 === 國立清華大學 === 材料科學工程學系 === 104 === Green electronics using biodegradable materials, such as protein-based polyelectrolytes, have attracted much interest in recently years because they are safe, nontoxic, and friendly to environment. In this thesis, we demonstrated two kind of green electronics devices, organic thin film transistors (OTFTs) and triboelectric generators (TEGs) fabricated with protein-based polyelectrolytes. The side chains of the amino acids in hydrated protein act as good sources of ions and the formation of the electric double-layer capacitors (EDLCs) enhances the device performance.
In OTFTs, spider silk protein was selected as gate dielectrics. The effective mobility (sat) of the pentacene OTFTs in saturation regime increases from 0.11cm2V-1s-1 in vacuum to 4.3cm2V-1s-1 in air ambient at ca. 70% RH. The corresponding the threshold voltage (Vth) value reduces from −6 V in vacuum to −0.5 V in air ambient. It points that mobile ions may increase the capacitance and the accumulation ability of carrier to enhance the device performance. In the other hand, the electrodeposition has been applied to silk-based OTFTs process successfully in order to pattern the dielectric in solution environment. The method can get high yield rate and high stability for the device.
In TEGs, gelatin/glycerol was chosen as the positive material to contact the Polytetrafluoroethylene (PTFE) thin film. When the relative humidity is raised from 20% to 60%, the output open-circuit voltage increases to 40-50V and the output short-circuit current increases to 1-2 μA. The device can provide an open-circuit voltage of 82 V and a short-circuit current density of 2.8 mA/m2 with a maximum power density of nearly 150 mW/m2 at a resistant of 100MΩ in air ambient ca. 60%RH, which is able to drive 100 LEDs simultaneously.
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