Mechanically tunable conductivity in piezoelectric semiconductors

压电半导体中的机械可调电导率

基本信息

批准号：
317658731
负责人：
Professor Dr. Hans-Joachim Kleebe
金额：
--
依托单位：
Institut für Angewandte Geowissenschaften (IAG)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/317658731?language=en
关键词：
Mechanically tunable conductivity piezoelectric semiconductors

项目摘要

The unique electrical properties in varistors and diodes rely on doping and interfacial potential barriers which are permanently implemented into the device. Here we provide a fundamentally new approach, geared towards piezoelectric semiconductors in which an interfacial electrostatic potential barrier can be reversibly tuned through external mechanical stress. The concept is related to piezotronics that so far has been focused, however, on Schottky barriers in nanofibers and yielded only small changes of potential barrier heights.This novel concept is fundamentally investigated using ZnO as semiconductor with high piezoelectric coefficient. The focus will be on single (ZnO/metal) and double (ZnO/ZnO) Schottky barriers with well determined orientations utilizing ZnO single crystals. Tailoring is then afforded using grain conductivity of the ZnO, work function of the metal and interface states determined by grain boundary misorientation and interface dopants. The additional flexibility arises due to the application of interfacial stresses during electric loading. Electrical characterisations in collaboration with other projects will be on density of electron states and electron mobility, in terms of impedance spectroscopy and I V curves at different frequency and temperature. A special challenge lies in the dichotomy of stress-tuned interfacial charge and semiconductor conductivity-enticed charge screening. At the same time, this project will provide polycrystalline ZnO to aid validation of modelling projects and affords electromechanical characterisation of polarisation texture of ZnO.

变种和二极管中的独特电性能依赖于永久实现在设备中的掺杂和界面电势垒。在这里，我们提供了一种从根本上提供新的方法，该方法针对压电半导体，其中可以通过外部机械应力对界面静电潜在的势垒进行可逆调节。该概念与到目前为止一直集中在纳米纤维中的Schottky障碍物上，仅产生较小的潜在屏障高度的变化。这种新颖的概念从根本上研究了使用ZnO作为具有高压电系数的半导体的新颖概念。焦点将放在单个（ZnO/Metal）和双（ZnO/ZnO）的Schottky屏障上，并确定了ZnO单晶的确定取向。然后，使用ZnO的晶粒电导率，金属的工作函数和由晶界不良方向和界面掺杂剂确定的界面状态来提供裁缝。由于在电加载过程中施加了界面应力，因此出现了额外的柔韧性。与其他项目合作的电特性将在电阻光谱方面与电子状态和电子迁移率的密度有关，并且在不同的频率和温度下进行I V曲线。一个特殊的挑战在于应力调节的界面电荷和半导体电导率输入电荷筛选的二分法。同时，该项目将提供多晶ZnO，以帮助验证建模项目，并提供ZnO极化纹理的机电表征。