OTFTs结构与器件性能

Configurations of OTFTs and the device performance

在重掺杂的Si衬底上分别制备了底电极(Bottom-contact organic thin-film transistors,BC-OTFTs)和顶电极(Top-contact organic thin-film transistors,TC-OTFTs)有机薄膜场效应晶体管,探讨了源、漏电极位置对器件性能的影响。结果表明,顶电极可以形成良好的欧姆接触,其器件的迁移率和开关电流比均高出BC-OTFTs器件三个数量级。研究了栅绝缘层的薄膜厚度对器件的电性能的影响。结果表明,在相同电压下,薄的绝缘层增大了沟道区域的电场,可积累更多的电荷,以填充更多的陷阱,使器件的场效应迁移率和工作电流得到了明显的提高。

Organic thin -film transistors based on the heavily doped silicon substrates were fabricated with two different designs ： bottom and top contact configurations （ referred to as BC - OTFTs and TC - OT- FFs, respectively）. The influence of configurations on the device performance was investigated. The resuits indicate that good contact can be obtained with top eontact; the mobility and the on/off ratio of TC - OTFTs are three orders of magnitude higher than those of BC - OTFTs. The thickness of gate insulator can also influence the device performance. At the same gate voltage, thinner gate insulator enhanced the field. As a result, more carriers can be accumulated to fill up more traps, so that the mobility and the operation current are enhanced subsequently.