II-VI族半导体纳米结构表面电荷转移掺杂及其光电性能调控的研究

II-VI group semiconductors show extraordinary optoelectronic properties. However, their wide applications in optoelectronic devices are limited by the unipolar electrical conductivity, low solubility of dopants and deep acceptor levels, which make it difficult to achieve efficient p- and n-type doping on II-VI nanostructures via complementary doping in a nondestructive manner. Alternatively, surface charge transfer doping has been emerging as a simple yet efficient technique to achieve reliable doping in a nondestructive manner, which can break through the technical bottleneck of II-VI nanostructures widely applied in nano-optoelectronic devices. In this project, we will systematically investigate the surface charge transfer doping on II-VI group semiconductor nanostructures and their electronic and optical properties, which can gain an insight into the fabrication of high-performance electronic and optoelectronic devices. The static electronic properties of II-VI nanostructures will be studied by using the first principles method to predict new and efficient p- and n-type surface dopants for II-VI nanostructures. Mechanisms for surface charge transfer doping will be explored by controlling the types and concentrations of surface dopants based on the dynamic electron transport results to targetedly tune the electronic and optical properties of II-VI group semiconductor nanostructures. Finally, the new electronic and optical properties of II-VI nanostructures are verified by characterizing the performance of devices. This project will be important in promoting the devices applications of II-VI group semiconductor nanostructures.

II-VI族半导体具有优异的光电性能，但由于自身单极性导电、掺杂剂低浓度和深的受主能级，传统掺杂很难实现高效、无损且可控的P型和N型掺杂，阻碍了II-VI族半导体在纳米光电子领域的应用。表面电荷转移掺杂具有高效、无损及可控等优点，可以突破II-VI族半导体广泛应用的技术瓶颈。本项目拟在实现II-VI族半导体纳米结构高效P型和N型掺杂基础上，对其光电性能进行调控，为构筑高性能纳米光电子器件提供理论和应用指导。通过静态电子结构计算，预测出可以实现II-VI半导体高效P型和N型掺杂的新型表面掺杂剂。然后改变掺杂剂类型和浓度，结合动态电子输运计算，分析表面电荷转移掺杂的机理，有针对性地调控II-VI族半导体纳米结构的光电性能。最后，通过器件性能表征验证II-VI半导体纳米结构表面电荷转移掺杂及其光电性能调控的机制。本项目的开展，对于促进II-VI族半导体纳米结构在光电子器件领域的应用具有重要意义。

本项目为实现II-VI族半导体纳米结构高效可控的P型和N型掺杂，通过静态电子结构和动态电子输运的计算，预测出了可以实现II-VI半导体高效P型和N型表面掺杂剂（F4TCNQ和BV），并分析了表面电荷转移掺杂的机理，有针对性地调控了II-VI族半导体纳米结构的光电性能，为构筑各型同质和异质结的高性能纳米光电器件奠定了基础。同时，基于表面电荷转移掺杂方法，构筑了高性能的场效应晶体管和探测微弱光的光敏三极管，推动了II-VI族这一类具有优良光电性质的纳米材料在纳米电子、光电子领域的应用。本项目在三年的执行期中，总体按预定的研究计划顺利进行，取得了预期的成果，项目主要目标基本完成，并在光催化和电催化方面有所拓展，为下一步研究工作的深入开展奠定了良好的基础。