稀土掺杂非计量比氮化硅薄膜的能量传递机理及量子剪裁应用

项目名称： 稀土掺杂非计量比氮化硅薄膜的能量传递机理及量子剪裁应用

项目编号： No.11504343

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 安永涛

作者单位： 中国工程物理研究院

项目金额： 24万元

中文摘要： 量子剪裁是提高硅太阳能电池效率的一条有效途径。传统的磷光体、玻璃陶瓷等下转换层基底材料，与硅电池材料晶格不匹配兼容，研发新型的基底材料具有重要意义。非计量比氮化硅具有多种敏化剂，可极大提高掺杂稀土离子的发光性能。本项目拟研究稀土(Tb3+-Yb3+，Pr3+-Yb3+) 掺杂SiNx薄膜材料的能量传递机理及其该类下转换层在太阳能电池中的应用。利用磁控溅射法制备薄膜材料，即通入N2和Ar气体产生等离子体，溅射靶材过程中氮与硅反应生成氮化硅。改变不同靶材功率和通入气体比值，调节基底Si/N比值和掺杂稀土离子浓度。利用热处理工艺优化薄膜样品微观结构，增加基底敏化剂密度，测量发光性质。重点研究基底敏化剂与稀土离子的能量传递机理及其对稀土离子体系量子效率的影响规律。通过对沉积最优下转换层薄膜的太阳能电池进行光电性能测试，实现提高转换效率的目标。研究成果将为新型光电转换材料的的研究和实际应用奠定基础。

中文关键词： 量子剪裁；能量传递；稀土离子；非计量比氮化硅；光电转换效率

英文摘要： Quantum cutting approach is a good way to improve photovoltaic efficiency of crystalline silicon solar cell. The traditionally used phosphor or class ceramic as downconversion matrix is, however, not compatible to silicon lattice. Thus, the investigation on new matrix is of great importance. Non-stoichiometric silicon nitride materials (SiNx) have some sensitizers towards rare earth (RE) ions, greatly enhancing the RE emission intensity. This proposal will study on the energy transfer mechanism in SiNx layers doped by RE ions (Tb3+-Yb3+ or Pr3+-Yb3+) quantum cutting in solar cell. The layers will be deposited by magnetron sputtering using N2 and Ar to generate plasma. During sputtering, nitrogen will react with silicon to form silicon nitride. The Si/N ratio and RE ions concentration will be tuned by N2/Ar and targets power. The micro-structures will be optimized via an annealing process to enhance sensitizers density for high emission intensity. This work will focus on energy transfer mechanisms between matrix sensitizers and RE ions, as well as their influence on quantum efficiency. The optimized layer will be deposited on silicon solar cell to approach our goal of high photovoltaic efficiency. Such work results will promote the fundamental research and future applications of novel downconvesion SiNx layers.

英文关键词： quantum cutting;energy transfer ;rare earth ions;non-stoichiometric silicon nitride;photoelectric conversion efficiency