光敏金属有机框架材料薄膜的组装和光电转换

Despite the increasing demands for alternative and sustainable energy sources, light-harvesting complexes in conventional dye-sensitized solar cells suffer from a variety of problems, including disorder, labile chemical bonding, and limited incorporation. This project involves in the preparation of highly robust metal-organic frameworks (MOFs) to combine titanium-oxo clusters and light-harvesting antennas in a crystalline hybrid extended framework. In addition, it is proposed to fabricate this class of MOFs into films on the transparent and conductive glass substrates via screening a variety of coating approaches, followed by the construction of a MOF-based photoanode. Moreover, a complete photovoltaic device will be assembled employing an electrolyte, and its photovoltaic performance will be fully characterized. Importantly, this project will achieve an ordered array of light-sensitizing components in dye-sensitized solar cells, and understand electron conductivity within MOF lattices and interfaces. Taking advantage of synthetic tunability and structural regularity residing in MOFs, this proposal will extend their applications in photovoltaic field, and offer a potentially low-cost and facile fabrication approach for a new class of dye-sensitized solar cells. This study will provide a systematic experimental research and theoretical arguments for electrical conduction in self-assembling organic-inorganic materials.

围绕当前可持续能源的日益递增，针对传统染料敏化太阳能电池存在的光敏基团无序、成键弱与比例低的问题，本项目拟制备具有高稳定性的金属有机骨架材料(Metal-Organic Frameworks，简称为MOFs)，在晶态杂化框架结构中组装氧化钛金属簇基团和光敏染料功能团，筛选镀膜工艺实现以透明导电玻璃为基底的MOFs薄膜，构建以MOFs作为主体材料的太阳能电池光电阳极，组装含电解质的太阳能电池完整器件并表征其光伏性能，实现染料敏化太阳能电池中光敏组分的规则排列，揭示MOFs晶格内部以及界面间的电荷传递。本项目集MOFs的合成可控性与高度有序晶格的优点，拓展MOFs材料在光电领域的新应用，提出低成本和简单合成工艺的新型染料敏化太阳能电池，为自组装无机有机杂化材料的电荷传导提供系统的实验研究和理论依据。

围绕当前可持续能源的日益递增，针对传统染料敏化太阳能电池存在的光敏基团无序、成键弱与比例低的问题，本项目围绕光敏金属有机框架材料（Metal-Organic Frameworks，简称为MOFs）薄膜在光电转换的应用展开。迄今为止，无法实现具有光电转换性能的MOFs主要受限于三个原因，分别是具有半导体特性的MOFs为数不多且禁带宽度无法调控；MOFs的电子传导能力较弱和不具备普适的MOFs镀膜手段。针对这些问题，本项目从高稳定性的光敏MOFs晶态材料的设计合成、建立普适的晶态MOFs镀膜方法和提升MOFs的离子传导性能三个方面着手，为构建MOFs基光电转化器件提供了良好的平台。首先，本项目研制了一系列具有优异光电性能且化学/光热稳定性出色的光敏MOFs晶态材料，并通过密度泛函理论计算和变温光物理表征手段确认其可调控的半导体禁带宽度和激子束缚能。 其次，本项目通过交错堆积致密二氧化钛薄膜和自组装多羧酸单分子膜，建立了一种在透明导电玻璃基底上普适的MOFs镀膜方法，成功拓展到四类具有不同金属中心且不同拓扑结构的羧酸基MOF材料。最后，利用MOFs中金属-羧酸配位键的动态特性实现了MOFs的剥层化学和一类单原子厚度的MOFs纳米片，大幅提升了MOFs的导电性；并以有机磺酸取代传统羧酸配体构建具有金属-配体缺失连接的三维多孔MOFs，提升了MOFs的质子传导能力。这些研究工作集MOFs晶态材料的合成、修饰与组装于一体，为拓展MOFs材料在光电领域的新应用提供了系统的实验研究和理论依据。