InGaN基一维纳米结构的压电光电子学效应研究

The emerging research and applications in piezotronics and piezophotonics arouse much attention in recent years. However, most researches are focused on ZnO-based devices. As a wide band-gap semiconductor, ZnO is only sensitive to ultraviolet irradiation. And the stable p-type doping of ZnO is still unsolved,which greatly hinders the application of ZnO piezotronic and piezophotonic devices for versatile, multifunctional and smart system. InGaN has unique merits over ZnO, eg.: the band-gap engineering of InGaN from the ultraviolet to the near infrared can be easily achieved by tuning the contents of In, And the preparation and doping technique for InGaN is much better developed than for ZnO. In this project, we will focus on one-dimensional InGaN nanostructures with desired morphology, structure and In contents. The relationship of the composition, structure, morphology and crystal orientation of the nanostructures will be investigated, as well as the modulation mechanism of transport properties, luminescence properties and optical response by piezophotonics effect in InGaN system. Piezophotonics enhanced optoelectronic devices based on one-dimensional InGaN nanostructures will be designed and fabricated, including InGaN photodetectors and light-emitting diodes. A comprehensive photonic-electronic-mechanic coupling testing platform for the research on piezotronics and piezophotonics effects will also be setup in this project, which will improve the fundamental unstanding of the piezotronics and piezophotonics.

压电电子学效应和压电光电子学效应是纳米科学领域近年来新兴的热点方向。然而，其主要研究多集中在ZnO基器件，其他压电半导体材料体系的压电光电子学效应亟待研究。ZnO是宽带隙半导体，仅对紫外区有光响应且p型掺杂困难，大大限制了压电（光）电子学器件的多样化、多功能化和智能化发展。InGaN带隙在紫外至近红外区间可调，具有宽光谱响应，且制备和掺杂工艺成熟。本项目拟选择InGaN一维纳米结构材料体系，探索形貌、结构、成分可控的InGaN一维纳米结构的制备工艺，探明纳米线组分、结构、形貌、取向的内在联系，建立纳米线操作、电极制作、封装及集成工艺；探明InGaN体系中压电势对输运性质、发光特性、光响应性等的调控机理，设计和制备出压电光电子学效应增强的InGaN光探测器、发光二极管等光电子器件；设计和搭建压电电子学和压电光电子学研究的光-电-力测试平台，完善压电电子学和压电光电子学效应科学体系。

压电效应是压电材料在应力作用下产生形变时出现的一种内部电势的现象。当GaN、ZnO和InN等代表的第三代半导体受到外加应力时，由于晶体中离子的极化而在材料内产生压电电势，可以有效改变金属-半导体的界面势垒和p-n结的输运性质。这就是压电电子学效应和压电光电子学效应。由于这两种新的物理效应所引起的全新物理现象和前所未有的潜在应用。.为此，本项目瞄准GaN等纳米材料的制备、表征、器件设计与压电电子学效应中的力-光-电耦合测试，获得了如下结果：（1）基于CVD方法，利用简单管式炉制备出多种高质量GaN微/纳米线，并研究了其光泵激光特性、构建了单根GaN纳米线忆阻器，并研究了相关性能。（2）利用MOCVD方法，生长了GaN、GaN/InGaN核壳结构，并基于这种很好的增益介质和谐振腔解耦合的器件结构，我们研究了波长连续、重复可调的激光器，当用外部泵浦光源激发 core-shell 结构的不同位置的时候，出射激光波长从372nm 移动到了408nm。在一根 10um 的结构上实现了 36nm 激光波长的移动，波长变化率 3.6nm/um。（3）设计和搭建进行压电电子学和压电光电子学研究装置和平台，建立压电电子学效应的研究方法，研究了多种基于压电纳米线的光电器件的压电电子学效应对其性能的调控，如CdS/PEDOT PSS柔性纳米LED阵列、柔性Si/ZnO LED阵列、柔性GaN/ZnO纳米线异质结的LED阵列、ZnO纳米线阵列焦平面光电探测器。.本研究应用了压电性质和电子学特性耦合性质，压电性质与光电子特性耦合的光激发过程，不仅开创了前沿研究领域，相关的先进技术也是目前全球新技术革命和工业革命竞争的核心技术之一，将对产业发展产生深远的影响。