多壳层上转换纳米晶与表面等离子体共振耦合效应在染料敏化太阳能电池中的应用研究

Dye-sensitized solar cells (DSSCs) have attracted extensive attention as one of the most promising alternatives to silicon-based photovltaic devices. It is essential to further improve the light harvesting capacities of dye sensitizers, specially the absorption of near-infrared photons, which is still a challenge so far. To address this issue, lanthanide-doped upconversion nanocrystals will be introduced in photoanodes to convert a broad spectrum of light into photons of a particular wavelenghth that can be absorbed by dye molecules. Furthermore, metallic nanostructures can be introduced as subwavelength antennas in which the plasmonic near-field is coupled to the dye, resulting in the increase of its effective absorption cross-section. After coupling with surface plasmon resonance (SPR), the light harvest of dye molecules and the power conversion efficiency of DSSCs based on lanthanide-doped upconversion nanocrystals will be further enhanced. This project will focus on the following issues: .1. To overcome the recombination of photoinjected electrons resulting from the introduction of lanthanide-doped upconversion nanocrystals and minimize their surface quenching effect, via the design of core/multi-shell structures. .2. To construct the architectures of core/multi-shell-structured lanthanide-doped upconversion nanocrystals and metallic nanostructures for achieving the effective coupling modes..3. To systematically investigate the coupling effect of upconversion and surface plasmon resonance on the performance of DSSCs..

染料敏化太阳能电池（DSSCs）被认为是最有可能取代硅基太阳能电池的新型光伏器件之一。如何进一步提高DSSCs中染料对光的吸收，特别是对近红外光的捕获利用，是目前该领域的研究热点和难点。针对这一问题，本项目拟在光阳极中引入稀土掺杂上转换纳米晶，将近红外光转换为染料分子可吸收利用的可见光，以提高染料对近红外光的吸收效率。并且，引入表面等离子体共振（SPR），将其与上转换效应结合，利用两者的耦合效应来共同提高染料分子对光的吸收，从而达到进一步提高器件光电转换效率的目的。.本项目拟重点研究：1、通过多壳层结构设计，解决稀土掺杂上转换纳米晶引入DSSCs中产生的电子复合问题并缓解其自身表面淬灭效应；2、构筑多壳层上转换纳米晶与纳米金属复合结构，实现上转换与SPR效应的有效耦合；3、上转换与SPR耦合效应对染料敏化太阳能电池性能的影响。

染料敏化太阳能电池（DSCs）因其成本低廉、制作工艺简单、柔性半透明等诸多优点，自1991年取得突破性进展以来，受到了世界范围内的广泛关注。如何进一步提高DSCs中染料对光的吸收，特别是对近红外光的捕获利用，是目前该领域的研究热点和难点。针对这一问题，本项目从以下三方面进行了研究：（1）制备二氧化钛纳米线阵列光阳极，并对其进行结构优化，获得较高电子传输效率的同时，引入金纳米颗粒，利用其表面等离子体共振效应，进一步提高DSCs器件的光电转换效率；（2）在光阳极中引入稀土掺杂上转换纳米晶，将近红外光转换为染料分子可吸收利用的可见光，以提高染料对近红外光的吸收效率。并且，引入表面等离子体共振（SPR），将其与上转换效应结合，利用两者的耦合效应来共同提高染料分子对光的吸收，从而达到进一步提高器件光电转换效率的目的；（3）在DSCs器件中，引入胆甾相液晶聚合物薄膜作为背反射层。通过对其组成成分的精确调控，获得具有不同反射波长的聚合物液晶薄膜。使得在保持器件柔性、透明等特性的同时，能够可控地增强DSCs对特定波段太阳光的吸收利用，进而显著提高DSCs的光电转换效率，不仅开创了液晶高分子功能材料在光伏领域应用的新思路，也开拓了DSCs在建筑集成光伏器件领域的应用前景。