以蛋白質介電層提升有機薄膜電晶體特性

Enhancing the performance of organic thin film transistors by protein gate dielectric layers

黃科霖(Ke-Lin Huang)

指導教授 ： 橫山明聰 ； 蘇水祥

義守大學/電機資訊學院/電子工程學系/碩士(2014年)

https://doi.org/10.6343/ISU.2014.00232

摘要

本研究旨在以不同蛋白質材料當作有機薄膜電晶體閘極介電層，提升有機薄膜電晶體特性。元件結構為：ITO glass/protein/pentacene/Ag，實驗結果發現當使用豬血清白蛋白為閘極介電層時，元件操作於VGS = VDS = -5 V條件下，相較於以PMMA為閘極介電層之有機薄膜電晶體，其飽和電流(IDS)從 -0.05 μA提升到 -13.2 μA，載子移動率(μ)從0.12 cm2/Vs提升至12.39 cm2/Vs，開關電流比(ION/OFF)從3.7×104降至5.6×103，臨界電壓(VT)則從 -23.1 V降低到 -1.8 V，顯示飽和電流與載子移動率各提升250倍與100倍。
由X光繞射儀(XRD)分析結果顯示以豬血清白蛋白為介電層之元件，其主動層薄膜結晶性較佳；原子力顯微鏡(AFM)檢測主動層薄膜表面得知晶粒尺寸增大且大小較為平均，呈現樹枝狀形式，這代表晶粒間有良好的互相連接，因此晶界的減少可降低介電層與主動層間的界面陷阱密度(Dit)，提升元件電特性。

關鍵字

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並列摘要

Various protein materials are used as the gate dielectric layer to fabricate organic thin-film transistors (OTFTs) and their electrical characteristics are characterized and discussed. Device structure is ITO glass/protein/pentacene/Ag. A control OTFT with a gate dielectric of PMMA is also fabricated. Comparing with the control device, experimental results reveal that the OTFT with a gate dielectric of pig serum albumin has the output current (IDS) from -0.05 μA to -13.2 μA, the field-effect mobility (μ) from 0.12 cm2/Vs to 12.39 cm2/Vs, the on/off current ratio (ION/OFF) from 3.7×104 to 5.6×103, and the threshold voltage (VT) from -23.1 V to -1.8 V. It demonstrates the IDS and μ is significantly enhanced about 250 and 100 times, respectively. The crystallinity of pentacene evaporated onto the gate dielectric is observed by X-ray diffraction (XRD) analysis. The pentacene shows better crystallinity when it is evaporated onto the pig serum albumin gate dielectric layer than PMMA layer. At the same time, atomic force microscope (AFM) images show that the grain size of pentacene becomes large and uniform. The grain clusters show a dendritic form, which indicates the pentacene has well-interconnected grains. Therefore, less grain boundaries cause the reduction of the interface trap density (Dit) between the dielectric layer and the active layer, thus enhancing the electrical characteristics of OTFT.

並列關鍵字

none

參考文獻

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