Actively manipulating electronic excitations in nanocrystals

由半导体材料制成的胶体纳米晶体类似于直径仅为几纳米的荧光珠。通过适当地选择材料并调整它们的尺寸和形状，可以将它们的光发射特性从紫外波长调谐到红外波长。迄今为止，纳米晶体已被开发用于基因组和蛋白质组生物测定、细胞染色和高通量筛选等领域，在这些领域中，它们用作荧光标记物，并且已经设想了在LED、激光器、光开关、光致发光器件、数据存储设备、催化、药物递送和其他生物医学测定中的更多应用。与通过分子束外延制备的自组装量子点相比，胶体纳米晶体可以通过相对简单和廉价的溶液方法制备，并且自由悬浮在溶剂或基质中，同时保持高的光学和电子稳定性。精确控制纳米晶体的尺寸和形状，例如量子点，棒甚至四脚体，使它们成为纳米科学和纳米技术的有前途的构建块。此外，胶体纳米晶体合成中的形状控制提供了前所未有的能力来调节固态量子结构与环境的相互作用，开辟了对光学和电子性质进行纳米级操纵的可能性。这个“第一批”提案旨在对胶体纳米晶体的基本性质进行关键实验研究。总体计划是开发新的应用程序的基础上，积极操纵的光电性能的纳米晶体和自组装方法，其在大型阵列设备配置的对齐。最终的应用范围从电场纳米传感器，单光子可调光源，光学存储元件和所有光学并行处理。

Colloidal nanocrystals made of semiconductor materials resemble fluorescent beads that are only a few nanometres in diameter. Their optical emission properties can be tuned from ultraviolet to infrared wavelengths by suitably choosing the material and adjusting their size and shape. To date, nanocrystals have been exploited in areas ranging from genomic and proteomic bio-assays, cell-staining and high-throughput screening, where they serve as fluorescence markers and more applications have been envisaged in LEDs, lasers, optical switches, photovoltaics, data storage devices, catalysis, drug delivery and other biomedical assays. Compared to self-assembled quantum dots made by molecular beam epitaxy, colloidal nanocrystals can be produced by comparatively simple and inexpensive solution methods, and are freely suspended in a solvent or matrix, while retaining a high optical and electronic stability. The precisely controlled size and shape of nanocrystals, such as in quantum dots, rods or even tetrapods, renders them promising building blocks for nanoscience and nanotechnology. Furthermore, shape control in the synthesis of colloidal nanocrystals offers unprecedented abilities to tune the interaction of solid state quantum structures with the environment, opening up the possibility of performing nanoscale manipulations of the optical and electronic properties. This 'First Grant' proposal aims for key experimental studies on the fundamental properties of colloidal nanocrystals. The overall plan is to develop novel applications based on the active manipulation of the optoelectronic properties of nanocrystals and on self-assembly methods for their alignment in large array device configurations. The ultimate applications range from electric-field nanosensors, single photon tunable sources to optical memory elements and all optical parallel processing.