基于纳米结构光电性能预测的原子键弛豫理论和实验研究

With the development of further investigations on nanostructures involved in nanocrystals and nanowires (nanocables) with positive curvature, and hollow quantum dots and nanotubes with negative curvature, there existed many novel physical and chemical phenomena and showed some important potential applications. However, it is hard to clarify the novel properties induced by nanosize effect under the current theoretical framework. Meanwhile, there is a big challenge to effectively predict the performances of nanostructures and the potential applications in devices by present theoretical methods. Therefore, it is urgent necessary to establish a new theoretical method to address the scientific problems mentioned above. In this project, we will study the chemical bonds-relaxation-theory regarding surface and interface of nanostructures with various geometry characters (solid size and surface morphology) and vibration mechanism under the condition of external fields (e.g. stress and temperature, etc.) approach based on the recently-developed thermodynamics on surface and interface energies. Our goal is to establish a general and analytic atomic bonds-relaxation-theory based on the nanothermodynamics and continuum mechanics, which can be as an effective tool to predict physical properties of nanostructures. Furthermore, the new developed atomic bonds-relaxation-theory will be demonstrated in experiment and can be suitable to deal with the intrinsic surface/interface energy states and energy level shifts as well as them processed by applied external fields in semiconductor optoelectronic nanomaterials, which reveals the physical mechanism of new phenomena and new science rules of photoelectric properties.

随着纳米结构研究的深入，无论是具有正曲率结构特征的纳米晶、纳米线（纳米电缆）还是具有负曲率特征的空心量子点、纳米管（纳米空洞）等等，都涌现出许多新奇的物理和化学现象，并且展现出一些重要的潜在应用。但是，由于这些新的纳米尺度现象无法在现有的理论框架内得到很好的理解，使得人们很难在理论上预测这些纳米结构的性能以及可能的器件应用。因此，迫切地需要人们发展新的理论工具来处理上述科学问题。本项目拟在所发展的纳米材料体系表-界能的热力学理论基础上，研究不同几何特征（尺度、形貌）的纳米结构表-界面在外场（应力、温度场等）作用下的化学键弛豫和振动机理，发展一种能够预测纳米结构物性的、普适性的、解析的、基于纳米热力学和连续介质力学的原子键弛豫理论，并将该理论应用于半导体光电纳米材料体系的本征及在外场作用下的表/界面能态和能级漂移等性质，同时从实验上予以验证，揭示体系光电性能中出现的新现象和新规律的物理机制。

随着纳米结构研究的深入，无论是具有正曲率结构特征的纳米晶、纳米线（纳米电缆）还是具有负曲率特征的空心量子点、纳米管（纳米空洞）等等，都涌现出许多新奇的物理和化学现象，并且展现出一些重要的潜在应用。但是，由于这些新的纳米尺度现象无法在现有的理论框架内得到很好的理解，使得人们很难在理论上预测这些纳米结构的性能以及可能的器件应用。因此，迫切地需要人们发展新的理论工具来处理上述科学问题。本项目在所发展的纳米材料体系表-界能的热力学理论基础上，研究了不同几何特征（尺度、形貌）的纳米结构表-界面在外场（应力、温度场等）作用下的化学键弛豫和振动机理，发展一种能够预测纳米结构物性的、普适性的、解析的、基于纳米热力学和连续介质力学的原子键弛豫理论，并将该理论应用于半导体光电纳米材料体系的本征及在外场作用下的表/界面能态和能级漂移等性质，同时从实验上予以验证，揭示了体系光电性能中出现的新现象和新规律的物理机制。