基于金属等离子体增强和光子晶体效应的复合上转换薄膜与光伏应用探索

Rare earth doped upconversion phosphors have demonstrated great application potential in the field of solar spectrum conversion and photovoltaic solar cells. However, there still exists some bottle problems, such as lower upconversion efficiency and narrower excitation band, thus it is difficlut to satify the pratical requirement of application. In this project，we will try to improve, as possible as we can, the upconversion efficiency of fluoride nanomaterials NaYF4:Yb,Er/Tm and oxides nanomaterials RE2O3(RE=Yb,Er,Sm and etc.) through their near field coupling with nobel metal nanoparticles (Au and Ag) and far field coupling with three dimensional photonic crystals with tunable photonic stop band. We will aslo try to expand the wavelength of excitation band of the upconversion nanomaterials through their coupling with the anisotropic nanorods. We will deeply study the impact of size, structure and shape of metal and rare earth nanocrystals, their copuling format and effective interaction distance on the luminescent enhancment factor of rare earth ions, and reveal the phyical essential of upconversion nanocrystals coupling with noble nanoparticles and three-dimensional photoic crystals. We will obtain upconversion nanofilms with high upconversion efficiency and broad excitation band, prepare novel solar cells based on upconversion principle and study their near infrared photovoltaic properties.

稀土上转换荧光材料，在太阳能谱转换和基于能量转换的光伏器件方面展示了诱人的应用前景，但还存在上转换效率低和激发谱带窄的瓶颈问题，无法满足太阳能谱转换的实际需要。本项目拟利用氟化物纳米晶NaYF4:Yb,Er/Tm和氧化物纳米晶(RE2O3, RE=Yb,Er,Sm等)与贵金属纳米颗粒（Au, Ag等）间的近场耦合，并结合其与带隙可控的三维光子晶体间的远场耦合，最大程度提高纳米晶的上转换发光效率。采用各向异性的金属纳米棒材料与上转换纳米晶之间的耦合，拓展其泵浦波长。深入研究稀土纳米晶和金属纳米材料的尺寸、结构、形貌以及它们之间的耦合方式与有效作用距离对稀土离子荧光增强特征的影响。揭示纳米上转换材料与金属纳米粒子和三维光子晶体间相互耦合的物理实质。获得具有高效率和宽激发谱带的上转换纳米薄膜材料，在此基础上对制备基于能量上转换原理的新型太阳电池和近红外光伏特性进行探索。

稀土上转换荧光材料，在太阳能谱转换和基于能量转换的光伏器件方面展示了诱人的应用前景，但还存在上转换效率低和激发谱带窄的瓶颈问题，无法满足太阳能谱转换的实际需要。本项目利用氟化物纳米晶和氧化物纳米晶与贵金属纳米颗粒（Au, Ag以及Au-Ag合金）以及半导体表面等离子体Cu1-xS间的近场耦合，并结合其与带隙可控的三维光子晶体间的远场耦合，大幅度提高了稀土纳米晶的上转换发光强度，提高的幅度最高达到3个数量级以上。深入研究了稀土纳米晶和金属纳米材料的尺寸、结构、形貌以及它们之间的耦合方式与有效作用距离对稀土离子荧光增强特征的影响，揭示纳米上转换材料与金属纳米粒子和三维光子晶体间相互耦合的物理实质。获得了具有高效率和宽激发谱带的上转换纳米薄膜材料，在此基础上制备了多种基于能量上转换原理的新型鈣钛矿太阳电池，获得了光电转换效率达到18.8%的鈣钛矿电池。在Adv.Mater.,ACS Nano, Adv. Func.Mater., Light.Sci. &Appl. , Nabo Today, Adv. Ener. Mater. , NanoEnery等国际顶尖与著名学术期刊上发表SCI论文63篇，研究成果获得了国内外同行的高度瞩目。