时间: 2014年5月6日 星期二 下午4:00

地点: 四川大学(望江校区)物理馆1楼103室

报告人: Prof. Leander Schulz, 四川大学

报告题目：Fabrication and characterization of transistors based on zinc tin oxide

报告内容: Transparent metal-oxides are one of the material classes that have been attracting substantial interest by research groups in the world owing to the potential to produce transparent displays. An often quoted application for these materials is in the automobile industry, where information about the car (speedometer, car status signs etc.) could be directly displayed in the windscreen. The most well-known examples for this material class are zinc oxide and its derivative indium gallium zinc oxide as they exhibit exceptionally high charge carrier mobilities. In addition to the high mobility, it is also desirable to enable large-scale industrial production, for instance through solution processing which usually results in an amorphous film morphology. For the presented study, zinc tin oxide (ZTO) was chosen as it exhibits high charge carrier mobilities of up to 40 cm2/Vs in the amorphous state and it can easily be processed by a sol-gel method and therefore offers a high potential for future commercial products. The seminar will start with a revision of basic properties of ZTO and essential transistor physics which is a particularly ideal beginning for undergraduate and graduate students with a background different from device physics. I will then continue with results of 4-point measurements which will be compared to 2-point measurements: The importance of the 4-point configuration will be demonstrated as different transport regimes obtained from temperature measurements that are otherwise hidden when applying only two terminals. Gated Hall devices similar in composition and structure to the transistors measured with the 4-point probes were characterized with a customized AC Hall measurement setup. I will show how to determine the Hall mobility in these kind of gate high-resistive samples, a parameter which otherwise with DC Hall measurements is only difficult to obtained. These results will be put into perspective to 4-point measurements. Eventually, I will present transistor characteristics where a top-gate structure with a “super-high-k” polymeric electrolyte was applied (still using ZTO): Together with capacitance measurements and data based on a low-k dielectric, the advantages of this dielectric is discussed.