低温金刚石对顶砧量子点荧光压力标定

We proposal this research plans of scientific issues for development of novel pressure calibrates with a high resolution of the measured pressure in the diamond anvil cell (DAC).The proposal is based on the items of 8 and 9th of “a novel approach for high resolution measurements of physical constants and parameters” and “a study of key scientific techniques in precision physical measurements”, issued by National Natural Science Foundation of China for the major research plan. We will carry out the work of pressure calibration in DAC in terms of the high sensitive pressure-induced shift of quantum dots (QDs) emission peak, combined with a new in situ applied pressure technique at low temperature, to explore the establishment of QD pressure calibration. This calibration will improve the pressure precision more than 100 times as compared with the Ruby due to the fact that the resolution is 100MPa for Ruby, whereas it is better than 1MPa for QDs at the same pressure-induced shift. At the same time, we will design of the DAC driven by a piezoelectric actuator (PZT) at low temperature. This proposal makes innovation in two fields, such as development of novel pressure calibration using QDs and a technique of tuning DAC in situ driven by a PZT at low temperature. Both the calibration and novel DAC will find their application in the fields of physics, chemistry, biochemistry and earth sciences.

本项目结合国家基金委的重大研究计划指南中培育项目第8和9项，“物理常数和物理参量高精度测量的新方法”和“精密测量物理关键单元技术攻关研究”范畴提出针对低温金刚石对顶砧压力精确测量标定科学问题为出发点。项目以固态半导体单量子点发光峰高灵敏的压力响应为新的压力标定物理体系，结合低温压力连续调谐新技术开展研究，探索建立可实用的基于量子点荧光的压力精确标定。压力测量将改进常规红宝石压力定标测量精度的100多倍，即红宝石定标精度为100MPa, 而预期量子点的定标精度优于1MPa。研制低温压电陶瓷推动金刚石对顶砧连续加压实验装置。项目的研究包含新的压力标定物理体系和低温连续加压实验技术的创新，该项目的完成将在物理、化学及生物等交叉学科领域基础研究得到应用。

项目结合高精度测量的新方法和精密测量物理关键单元为技术攻关，提出针对低温金刚石对顶砧压力精确标定的科学问题。以固态半导体单量子点发光峰高灵敏的压力响应为新的压力标定物理体系，结合低温压力连续调谐新技术开展研究，探索建立可实用的基于量子点荧光的压力精确标定方法。设计和制备电驱动金刚石对顶砧低温连续加压装置，测量压电陶瓷低温下的伸长量和伸长量与外加偏压的关系。根据低温压电陶瓷金刚石对顶砧施加压力的实验技术，设计小型金刚石压力装置与压电陶瓷对接装置。在测量样品方面，生长低密度InAs/GaAs单量子点，开展低温单量子点光谱测量、谱线半高宽度的测量和量子点的压力系数标定等实验研究。在温度10-80K，根据通用的红宝石的R1峰的压力移动数据，确定 InAs 单量子点发光波长与压力的关系，得到量子点发光峰波长（或峰值能量）移动与压力的函数关系，建立基于量子点发光峰压力移动的压力标定计算公式，给出定标精度和误差等关键物理参数值。测量发光峰强度的变化，发光峰线宽的变化，发光峰温度漂移与压力系数的关系，以此给出可使用的压力定标范围和压力定标的可重复性。取得的主要研究成果有：设计制备了电驱动金刚石对顶砧低温连续加压装置，测量了压电陶瓷低温下的伸长量，低温下伸长量与偏压的关系，压电陶瓷低温移动的迟滞特性。得到样品室的工作温度为18-20K。基于压电陶瓷的外加电压，0-150V，实现低温约 2GPa 的压力可调范围。若外加电压 0-300V，可实现 0-4GPa 的压力连续调谐范围，而且压力调谐精度达到1MPa。围绕低密度InAs/GaAs单量子点的生长、低温单量子点光谱的测量、谱线半高宽度的测量和量子点的压力系数标定等开展实验研究。发展了电驱动金刚石对顶砧低温连续加压装置。结合荧光单光子光谱测量实验技术，实现了低温原位压力调谐，并测量了单量子点的压力行为。发表标注的SCI学术论文 8篇。