高可控GaN基纳米线及其异质核壳结构的生长与性能研究

GaN has became a promising candidate for applications of nanodevices with its excellent performance. It is of key importance to synthetize high-quality GaN-based nanowire with controlled size and spacial density for developing high-performance nanodevices. Taking into account this fact, the applicant proposes a rational method for the synthesis of catalyst-free GaN-based nanowire on patterned silicon(Si) substrate, which combined the technology of wet chemical etching and the epitaxial relationship between GaN and different facet of Si. Then we also explored the optically pumped properties of the as-synthesized GaN-based nanowire, and the factors and mechanism of response performance of GaN nanowire based sensitive device, such as ultraviolet detector and gas sensor, were studied. Under the premise of ensuring crystal quality, the size, density, doping and structure of GaN-based nanowire could be highly controlled by this synthesis way, what is more, it facilitates to design and growth high quality heterojunction core-shell nanowire with sharp interface. So, the performance of as-synthesized nanowire could be well controlled by regulating its physical properties and chemical properties. In this project, the regulation mechanism for the generation and transport properties of carriers in the GaN-based nanowire, which were caused by the piezoelectric effect, will be fully explored. And we will also further research the impact mechanism of carrier concentration and mobility in GaN nanowire for the sensitive devices. This will open up a new way to explor the potential applications of GaN-based nanowire.

GaN材料具有诸多优良性质，使其在纳米器件应用方面有着独特的优势。制备出性能优良、尺寸和密度可控的GaN基纳米线是研制高性能纳米器件的关键。本项目采用湿法化学刻蚀技术，利用GaN材料在硅不同晶面的异向外延特性，提出一种免催化剂在图形Si衬底上生长GaN基纳米线的方法。在此基础上，开展GaN基纳米线光泵浦激光特性研究，以及GaN基纳米敏感器件响应性能的影响因素及机理研究。该制备方法在保证晶体质量的前提下，可实现对纳米线生长尺寸、密度、掺杂、结构等的高可控性，并利于生长界面陡峭的异质结核壳结构，从物理特性和化学特性同时实现GaN基纳米线的调控。项目还将研究压电效应对GaN基纳米线体系中载流子的产生和输运特性的调控机理，揭示载流子浓度和迁移率对GaN基纳米线敏感器件响应特性作用机理，发现GaN纳米线的潜在应用性能。

GaN纳米材料具有诸多优良性质，使其在纳米器件应用方面有着独特的优势。制备出性能优良、尺寸和密度可控的GaN基纳米线是研制高性能纳米器件的关键。本项目采用湿法化学刻蚀技术，利用GaN材料在硅不同晶面的异向外延特性，实现了空间密度、尺寸、掺杂、结构等高度可控的GaN基纳米线制备，并生长出界面陡峭的异质结核壳结构，从物理特性和化学特性同时实现GaN基纳米线的调控。在此基础上，项目深入开展了GaN基纳米线性能研究，并研制了GaN基纳米器件。. 研究表明， GaN基纳米线具有良好的光学性能和电学性能，InGaN/GaN量子阱核壳结构在较低阈值下实现了光泵浦激光发射；制备了AlGaN/GaN核壳结构，实现了AlGaN/GaN二维电子气，深入研究了压电效应对二维电子气传输的影响机制，表明压电效应能有效提升二维电子气浓度，并理论研究了压电效应对二维电子气的影响机理，研制出基于单根AlGaN/GaN纳米线的高电子迁移率晶体管；制备了GaN纳米线同质结发光二极管，并深入研究了压电效应对同质结发光二机管的影响，表明压电效应由于能有效降低势垒高度，并实现空穴载流子在界面的聚集，从而明显提升了同质结发光二极管的发光效率；制备出了较高性能的GaN单根纳米线紫外探测器，实现了Si/GaN纳米线的紫外和近红外自驱动探测，并研制出GaN纳米线集成阵列紫外探测器。通过项目的实施，在Advanced Materials（IF=21.950）、Nano Lett（IF=12.080）、Nano Energy（IF=13.120）、ACS applied materials & interfaces（IF=8.097）、ACS photonics（IF=6.880）等国际权威刊物发表SCI收录论文13篇，授权发明专利4件，受理发明专利6件，培养研究生10名。