氟磷酸玻璃基质中PbS/PbSe量子点与稀土离子之间的能量传递调控与上转换光学性质研究

The main problem for up-conversion of rare earth ion is its narrow excitation bandwidth and relatively low conversion efficiency, which severely restricts its wide application in optoelectronic technology. Sensitization with near-infrared quantum dots is a possible approach to break through the current predicament for up-conversion of rare earth ions. In the present research project, therefore, we will systematically investigate the control and regulation means of broadband sensitization from near infrared quantum dots to rare earth ions and the mechanisms on up-conversion enhancement in the quantum dots and rare earth ions co-doped system. During the process of this research, we will use glass-ceramic as matrix, rare earth ions as up-conversion center and PbS, PbSe quantum dots as sensitizers. We will design and develop rare earth doped fluorophosphate glass containing quantum dots as nano-crystals, adjust and control the growth and distribution of quantum dots in glass matrix, explore the properties and controlling means of various energy transfers between quantum dots and rare earth ions, simulate and analyze the luminescence kinetics, reveal the physical mechanisms of quantum dot sensitized up-conversion process. On the basis, the integrated physical environments for cooperative sensitization to rare earth ions by various energy transfers will be optimized and efficient up-conversion under broadband light excitation will be achieved. The project reasonably combines the broadband near-infrared absorption of quantum dots with efficient up-conversion of rare earth ions. Thus it is expected to develop a novel up-converting method with broad near-infrared excitation band, referring a new means for efficiency and property improvement of infrared detectors, solar cells and other related optoelectronic devices and technologies.

狭窄的激发带宽与较低的转换效率是稀土上转换发光面临的主要困境，严重制约它在光电子技术领域的广泛应用。近红外量子点敏化是突破当前稀土上转换困境的可能途径。为此，本项目以玻璃陶瓷为载体，稀土离子为上转换中心， PbS、PbSe量子点为敏化剂，系统研究近红外量子点宽频带敏化稀土离子的调控手段与上转换的增强效应。项目将设计和研制以量子点为纳米晶的稀土氟磷酸盐玻璃陶瓷，调控量子点在玻璃基质中的生长与分布，探索量子点与稀土离子之间各种能量传递的规律及其控制方法，模拟分析其发光动力学过程，揭示量子点敏化稀土离子的上转换物理机制。在此基础上，优化各种能量传递协同敏化稀土离子的综合物理环境，获得宽频带近红外光激发下的高效上转换发光。项目将量子点的宽带近红外吸收特性与稀土离子的高效上转换性能有机结合，有望发展出一种宽频带上转换的新手段，为红外探测、太阳能电池等相关光电子器件与技术的增效与改性提供一种新方案。

成功制备多个Mn4+掺杂的新型氧化物发光材料，寻找出对激活离子发光性能的调控手段。研究了Mn4+离子在新的Ba6Y（Gd）2W3O18 和Li6SrLa2Sb2O12基质中的发光特性。制备出了能同时将紫外光和绿光转化为深红光的Mn4+掺杂Ba3Y2WO9材料。特别在双钙钛矿结构氧化物中利用离子对替换的方法，优化了其发光性能，实现了Mn4+在K0.5La0.5SrMgWO6中发光量子效率达到达97.7%的新突破。完善了利用双激活中心发光材料监控和测量激光波长的技术思路，研究了Mn4+、Cr3+共掺杂Li2MgTiO4、La2ZnTiO6和BaMgAl10O17的中心发光材料，探讨了它们热稳定性和测量灵敏度。所制备的双激活中心发光材料用于波长监测的最大相对灵敏度可达10%。获得了一类具有温度传感和激光波长测量双重功能的Mn4+、Eu3+共掺杂K0.3La1.233MgWO6的发光材料。以Ni2+离子为敏化剂，研究了Ni2+离子对Er3+和Tm3+离子的敏化上转换。在LiGa5O8基质中获得了900nm-1300nm波段范围激发下Tm3+离子800nm的上转换发光，在MgGa2O4获得了900nm-1700nm激发下的Er3+离子660nm的上转换红光，实现了宽带敏化上转换的新突破。研究了上转换过程中的稀土离子对Mn4+离子的敏化，通过Mn4+离子与HO3 +离子上转换发光的重叠，获得最大宽度覆盖640-770nm的上转换发射。此外，研究了Mn4+和Cr3+离子对Yb3+离子的敏化发光，研究了Ce3+ →Er3+ →Ho3+的间接敏化，获得了相应的近红外发光的敏化增强。项目研究中获得了一批高效和独具特色的发光材料，寻找到了一些提高发光效率的技术途径，实现了宽带激发上转换发光的研究目标。项目共发表SCI论文19篇，申请发明专利5项，其中已授权发明专利1项。