高開關電流比之高分子垂直電晶體

Abstract

有機半導體為近年來學術界積極開發知新穎元件，有機半導體主要訴求為低成本以及高效率，還有穩定性。在成熟的平面場效電晶體製程下做了許多的改進，但是在高效率前題下往往需要是極佳的表面性質，也用到了矽基板還有氧化矽等材料，做出來的效果也往往需要極大的電壓，對於真正的應用有極大的障礙。於是我們採用垂直的電晶體結構，此結構類似於真空管的運作原理。我們最佳化此結構可以達成甚至超越同樣材料平面電晶體的開關比，以及更小的操作電壓，更大的輸出電流。這篇提出了三大類結構，第一個是下方注入的結構，擁有較高的開關比，並且探討了控制閘極在空間位置上的影響。第二種是上端注入，擁有較好的材料相容性，比較不受ITO功函數限制，相信對於未來空氣穩定材料有相當的助益。第三種基於第一種結構簡化，利用自我組裝分子來取代部分絕緣層，並使用溶液緩慢乾燥的技術來達成更高的輸出電流並抑制控制閘極的漏電。 這篇論文確實提供了垂直空間限制電荷電晶體相當的資訊以及探討，也提出相當可靠並且簡單的製程。

High performance OTFT has been studied for many years. The most important issue is low cost, high performance, and stability. By the mature process of MOSFET, OTFT has been improved a lot, but unfortunately most of them are fabricated on silicon base or thermal oxide, this is expensive and not suit for low cost requirement. For future application, we fabricated a vertical organic transistor, which is similar to vacuum tube. We achieved a comparable performance of on/off ratio, and lower driving voltage, increasing output current compared to the FET made by same P3HT materials. Here we purposed three kinds of SCLT devices. First is bottom injection SCLT, which owns highest on/off ratio. And then we discussed the impact of grid position in the SCLT space. The second is top injection which is good for new ambient material, because we won’t be limit by ITO work function. Third is simplified from the first structure, we use SAM to replace insulator layer, and use in solvent annealing SCLT devices, which has great output current but higher grid leakage current. By using SAMs treatment, we get higher current gain. Here we discussed a lot of information and process about SCLT, it’s useful for future developing.