基于稀氮砷化镓（Dilute nitride GaNAs）的近红外自旋放大纳米线激光器的研究

Semiconductor nanowires (NWs) are the most suited candidate to realize nano-lasers owing to their naturally formed optical cavity and prominent emission properties. To date, NW lasing has been demonstrated from ultraviolet (UV) to near-infrared (NIR) spectral range, among which NIR NW lasers possess great potential in optical communication, bio-imaging and sensing. There are yet several material issues associated with NIR NWs, including high alloying content and resulting lattice mismatching and strain, which adversely affect NW’s electronic states and optical properties. In addition, current NW lasers haven’t harnessed the spin degree of freedom of photons, which is of immense technological importance in spin quantum information processing and communication. Dilute nitride GaNAs has been emerging, in recent years, as a promising material for fabricating NIR NWs, thanks to its giant band-bowing effect. Furthermore, its unique Ga interstitial centers offer strong spin amplification effect, which can enhance the spin polarization of conduction band electrons and emission efficiency. Based on these material merits, this project will fabricate the GaNAs NWs through bottom-up and town-down strategies and investigate the mechanism of Ga interstitial formation in NWs. Finally, by combining the NW optical cavity with spin-amplified emission property, we aim to achieve NIR spin-amplified lasing from GaNAs NWs at room temperature.

半导体纳米线具有天然的微腔结构和优良的发光性质，是实现纳米激光器的理想载体。其中，近红外纳米线激光器在光通讯、生物成像及传感领域有着重要的应用价值。然而，目前近红外纳米线存在合金浓度高及由此造成的晶格失配和应力问题，影响了纳米线的电子能态及光学性质。此外，近红外纳米线激光器并未利用光子自旋维度，对这一性质的利用将极大拓展其光电应用，如：量子光信息处理及通讯。近年来，稀氮砷化镓材料 Dilute nitride GaNAs由于具有巨带隙调控效应，成为制备近红外纳米线光电器件的理想材料。其特有的Ga间隙原子中心具有自旋极化效应，能够有效放大增强导带电子的自旋极化率及发光效率。基于这些材料优点，本课题将通过自下而上和自上而下两种方式制备GaNAs纳米线，系统研究Ga间隙原子在纳米线中的形成机理。通过结合纳米线光学微腔和GaNAs优异的自旋光学性质，最终实现室温下近红外波段的自旋放大纳米线激光器。

半导体光电芯片是突破后摩尔时代信息处理与传输瓶颈的重要技术路线。其中，面上片上集成的微纳光源器件承担光信号的产生，处于信息链路的第一环，具有重要的作用。本项目围绕低维半导体光源器件开展了深入系统的研究，研究内容与成果阐述如下：（1）基于CdS纳米带实现电调控波长调谐激光器：利用电声子耦合以及电流焦耳热效应分别实现自发辐射以及受激辐射20nm与10nm的片上集成电调谐，此外实现20dB的激光电调制深度，该工作为片上可调光源提供了新的技术方案；（2）基于CdS-WSe2混合p-n异质结实现波导集成LED器件，获得WSe2电泵浦光发射，并实现在CdS纳米带波导中的高效光传输，该工作提供了实现光源与波导集成的新方法；（3）基于GaNP纳米线实现亚衍射尺寸非线性光源，通过N合金极大提升二阶非线性系数，利用金属等离激元微腔实现光场限域，获得380倍二次谐波输出增强，该工作为片上非线性集成光源提供了新的解决方案；（4）在二维材料研究方面，通过Ga原子以及O原子掺杂钝化，实现MoS2以及WS2荧光输出增强，量子效率提升超过一个量级，研究表明Ga原子以及O原子能够有效填补S空位，钝化深能级缺陷并提升材料荧光性能，相关成果为制备高性能二维光电材料提供了重要手段。.本项目围绕低维光电材料制备、改性以及光源器件构筑所取得成果为发展新一代高性能光电集成芯片奠定了重要基础。

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