II-VI族掺杂半导体纳米线的单源前驱体SLS掺杂策略制备、发光机制与调控研究

One-dimensional doped semiconductor nanowires,compared to other doped nanocrystals, exhibit quantum confinement effects in two directions coupling with atomic energy states from doped ions as well as electron and exciton transport in other unconfined direction, which make them suitable candidates for nanophotonics and optelectronics applications. Recent advances in the chemistry of colloidal semiconductor nanocrystal doping have led to new materials showing fascinating luminescence and/or magnetic-optical properties of potential technological importance. Spherical colloidal nanocrystals doped with Mn or Cu ions have been widely studied, but anisotropic-doped nanocrystals such as nanowires,nanoplates are rather exceptional. To achieve high quality doped semiconductor nanowires, it is much aspired to develop simple, gernal and easy scale up synthetic route. This proposal aims to develop single source precusor solution-liquid-solide doping strategy for high qualtiy II-VI group doped semiconductor nanowires.We proposed a simple and general single soource precusor solid-liqiud-solution(SLS)doping strategy for II-VI colloidal doped naowires. With this strategy, we can synthesize Mn, Cu, Ag, Eu doped II-VI CdS and ZnSe nanowires. By optimizing the colloidal chemistry, we will be able to tune the morphology, diameter as well as the doped element and concentration,which will certainly give tunable phsycial properties. Fundamental research challenges must be addressed to enable us to understand and improve the synthetic chmistry behind the doping process as well as the PL properites of resulting nanowires. This proposal represents an interdisciplinary approach to the colloidal nanocrystal synthesis,nanomaterials, spectroscopic study, spectroscopic study and the exploration of devices. As such, the proposed work not only benefits physical chemistry science, but also provides competive opportunities for the realization of novel luminescent materials, even novel fuctional devices.

与零维掺杂纳米晶相比，过渡金属掺杂的半导体纳米线兼具量子尺寸限域效应、掺杂离子的自旋和能级调控、良好的电子输运和激子迁移通道，是一类具有特殊发光性质的材料，可望成为构造纳米光子和自旋光电子器件的理想单元。为获得高质量II-VI族掺杂半导体纳米线的简单、可控、容易放大的溶液相合成方法，理解其发光机制并对其发光性质进行调控，本项目在文献调研和前期探索的基础上，提出了II-VI族掺杂半导体纳米线的单源前驱体SLS(溶液-液-固)掺杂制备策略，通过其掺杂生长机制研究、合成路线设计和反应条件优化，实现掺杂纳米线的尺寸、形貌、晶体结构以及掺杂种类和浓度的控制；进而利用多种光谱手段，研究掺杂纳米线的发光性质,结合材料表征,初步阐明其发光机制；在此基础上，对材料进行理性设计和发光调控，获得具有较好稳定性、高荧光量子产率、发光光谱可调的掺杂II-VI族半导体纳米线材料，并探索其发光LED应用。

与零维掺杂纳米晶相比，半导体纳米线兼具量子尺寸限域效应、掺杂离子的自旋和能级调控、良好的电子输运和激子迁移通道，是一类具有特殊发光性质的材料。本项目发展了SLS(溶液-液-固)掺杂制备策略，通过掺杂生长，实现了CdS纳米线的掺杂种类和浓度的控制，通过调控Mn离子的掺杂浓度实现了白光发射；进一步将SLS前驱体合成拓展到CdSexS1-x合金化纳米线的制备中，获得了兼具偏振特性、发光可调、颜色饱合的CdSexS1-x合金纳米线，所制备的合金纳米线的荧光量子效率较之前报道(<0.1%)提高2个数量级(8.8%)，通过温度依赖的稳态和时间分辨荧光光谱，结合材料表征，初步阐明其激子和缺陷复合发光过程；传统的SLS生长一般采用原位制备的Bi纳米颗粒作为晶种诱导生长，本项目开展了Cu2-xS纳米晶为晶种的SLS制备研究，通过发展合成化学获得了不同晶相的五种纳米晶材料，利用Cu2-xS纳米晶初步尝试了SLS生长，获得了pn异质结纳米线。以上研究进展为发展偏振发光材料提供了合成技术和材料基础。相关结果已接受发表SCI收录论文3篇，另外1篇论文在准备投稿中，授权专利1项，在国内外学术会议上做邀请报告2次。