基于量子点发光的纳米尺度压力传感材料研究 | |
Alternative Title | Research on Nanoscale Pressure Sensing Materials Based on the Photoluminescence of Quantum Dots |
王俊刁 | |
Thesis Advisor | 白以龙 ; 肖攀 |
2022-11-29 | |
Degree Grantor | 中国科学院大学 |
Place of Conferral | 北京 |
Subtype | 博士 |
Degree Discipline | 固体力学 |
Keyword | 量子点,光致发光,压力传感器,核-壳结构,第一性原理 |
Abstract | 微/纳机电系统的发展、爆炸/冲击等极端压力环境下的压力探测对压力传感器提出新的要求:空间分辨率达到μm或nm量级、可探测的压力达到MPa或GPa量级、可应用于复杂的温度/压力环境、非接触式等等。然而,目前常用的压力传感器难以同时满足上述需求。量子点作为纳米尺度的光致发光材料,因其独特的能级结构和压力相关的发光特性,有望成为一种新型的纳米尺度压力传感材料。目前关于量子点在压力作用下的发光响应开展了初步研究,但是对于更复杂、更接近压力传感器实际应用工况的研究甚少,如温度变化、反复加-卸载等条件。同时,量子点尺寸、结构、材料对其受压发光特性的影响缺乏系统对比和分析。更重要的是,量子点发光特性随压力变化的微观机理研究也有待丰富。本论文通过设计搭建实验平台,针对不同尺寸、不同结构的CdTe、CuInS2以及核-壳型CuInS2/ZnS量子点,开展了不同温度、压力以及反复加-卸载等复杂实验条件下的发光特性研究,以量子点发光强度和光谱峰值能量两个主要荧光特征为指标揭示了不同量子点在不同实验条件下的发光响应规律。进一步,采用第一性原理计算研究了不同尺寸量子点的能隙在不同应变模式下的变化规律,从微观角度探究了光谱峰值能量随压力变化的机理。具体研究工作包括以下几方面:
本论文的研究成果有助于理解复杂加载条件下不同量子点的发光响应以及微观机理,对基于量子点发光的压力传感材料的研究提供了新思路,并为新型纳米尺度压力传感器的设计和应用提供了参考和指导。 |
Other Abstract | Pressure sensing for complex application scenarios, such as micro/nano electromechanical systems and the extreme conditions induced by explosion or shock compression, has placed new demands on pressure sensors: spatial resolution to the micron or nanometer scale, pressure range at the MPa or GPa level, responsible in complex temperature/pressure environments and non-contact detecting. However, the existing pressure sensors are basically difficult to meet the above requirements simultaneously. As nanoscale photoluminescence (PL) materials, quantum dots (QDs) are expected to become a new type of nanoscale pressure sensing materials due to their unique energy level structure and pressure-related PL properties. At present, preliminary progress has been obtained in the research on the response of PL properties of QDs under pressure, while experimental studies on more complex application conditions of pressure sensors are less involved, such as temperature, repeated loading-unloading, etc. Moreover, the effects of QD size, microstructure and material type on PL characteristics under pressure have not been systematically analyzed. More importantly, the microscopic mechanisms of the PL responses of QDs with pressure also need to be investigated. In the dissertation, an experimental platform was designed and built. Then, experiments of PL response were carried out on CdTe, CuInS2 and core-shell CuInS2/ZnS QDs with different sizes and structures under several complex conditions such as different temperatures, pressures and cycles of pressure loading and unloading. Two main fluorescence characteristics of the PL, namely, PL intensity and spectral peak energy (EPL ), were used as indicators to reveal the law of PL response for different QDs under different experimental conditions. Furthermore, the energy gaps of QDs of different sizes were studied under different strain patterns using first-principles calculations, and the mechanism of the response of EPL with pressure was investigated from a microscopic perspective. The specific research work includes the following aspects.
Results in the dissertation help to understand the PL response and microscopic mechanism of different QDs under complex loading conditions. It provides new ideas for the study of pressure sensing materials based on the PL of QDs. Moreover, the results also provide valuable reference and guidance for the design and application of novel nanoscale pressure sensors. |
Language | 中文 |
Document Type | 学位论文 |
Identifier | http://dspace.imech.ac.cn/handle/311007/91182 |
Collection | 非线性力学国家重点实验室 |
Corresponding Author | 王俊刁 |
Recommended Citation GB/T 7714 | 王俊刁. 基于量子点发光的纳米尺度压力传感材料研究[D]. 北京. 中国科学院大学,2022. |
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