Department of Electrical & Computer Engineering, University of Alberta, Edmonton, AB T6G 2 V4 Canada.
ACS Appl Mater Interfaces. 2012 Mar;4(3):1423-8. doi: 10.1021/am201656h. Epub 2012 Mar 12.
Solution-processed ZnO thin films are attractive as active materials in thin film transistors (TFTs) for low-cost electronic device applications. However, the lack of true enhancement mode operation, low mobility, and unreliability in transistor characteristics due to the high density of traps and other defects present challenges in using such TFTs in circuits. We demonstrate in this report that the electrical characteristics of such TFTs can be improved by source injection barriers. Asymmetrical Schottky source metal-oxide-semiconductor field-effect transistors (MOSFETs) have been fabricated by utilizing heavily doped solution-processed ZnO as the active layer. n(+)-ZnO was obtained by using triethylamine as the stabilizer in the solution process instead of the more commonly used monoethanolamine. Au was chosen for source metallization to create a Schottky contact to the ZnO and an Al ohmic contact was chosen as the drain. Voltage applied to the gate induced field emission through the Schottky barrier and allowed modulation of the drain current by varying the width of the barrier. By operating the asymmetrical MOSFET when the Schottky contact is reverse biased, effective control over the transistor characteristics was obtained.
溶液处理的 ZnO 薄膜作为活性材料在薄膜晶体管（TFTs）中具有吸引力，适用于低成本电子设备应用。然而，由于陷阱和其他缺陷的高密度，这种 TFTs 在电路中存在真正的增强模式操作、低迁移率和不可靠性的挑战。我们在本报告中证明，通过源注入势垒可以改善这种 TFTs 的电特性。通过利用重掺杂溶液处理的 ZnO 作为有源层，制造了不对称肖特基源金属-氧化物-半导体场效应晶体管（MOSFETs）。在溶液处理中使用三乙胺代替更常用的单乙醇胺作为稳定剂，得到了 n（+）-ZnO。选择 Au 作为源金属化，以在 ZnO 上形成肖特基接触，选择 Al 欧姆接触作为漏极。施加到栅极的电压通过肖特基势垒诱导场发射，并通过改变势垒的宽度来调制漏极电流。通过在肖特基接触反向偏置时操作不对称 MOSFET，可以获得对晶体管特性的有效控制。
