新型内嵌硫化物团簇富勒烯的有效制备﹑能级调控及光伏特性研究

It has been approved that the LUMO,HOMO energy levels as well as the band-gaps of electron-donors and electron-acceptors might impose significant influence on the open-circuit voltage (Voc) and energy conversion efficiency (η) of the related photovaltaics. Fullerene C60 has been widely used as a good electron acceptor for preparing various photovaltaics. In addition, it has been revealed that some specific functionalizations of fullerene cage could increase, to a limilted extent, the LUMO energy levels of fullerenes, thus giving rise to better photovaltaic performance. However, encapsulation of a cluster inside the fullerene cage can induce a more significant change of MO energy levels, which may improve the matching between the MO energy levels of donor and acceptor. Therefore, this project proposes to study a series of novel sulfide clusterfullerenes,including their efficient productions, characterizations and the methods for manipulating their energy levels. The aim is to develop a variety of novel fullerene-based acceptors and donors, and to investigate the typical or atypical mechanism of photovaltaic effect. Hopefully, all these works will help to complete the system of fullerene-based photovaltaic materials and the related theory.

近年来的研究表明电子给体和受体材料的能级结构包括LUMO/HOMO能级水平，带隙等是影响有机光伏器件的开路电压（Voc）及能量转换效率（η）的重要因素。富勒烯C60作为优异的电子受体材料已经被广泛的用于光伏器件的制备，通过碳笼表面的化学修饰还可以进一步调控其LUMO能级，优化其光伏性能，但调控幅度相对有限。而在富勒烯碳笼内部嵌入团簇则有可能较大程度的调控富勒烯的能级结构，使得给体材料与受体材料更好的满足能级匹配的要求。因此本项目拟对新型内嵌硫化物团簇富勒烯展开研究，包括其有效制备表征，明确其能级调控机制等，目的是开发具有优异光伏性质的新型富勒烯受体或给体材料，并探索或证实相关的典型或非典型光伏效应产生的机理，为富勒烯光伏材料的进一步发展提供理论依据。

在本项目资助下，我们进一步发展了电弧放电制备内嵌富勒烯的方法，采用弱氧化性的CO2气体作为氧源，实现了高选择性制备内嵌金属氧化物团簇富勒烯Sc2O@C2n(n=35-47)，并分离表征了一系列内嵌金属氧化物团簇富勒烯。表征结果显示：与普遍研究的金属氮化物团簇富勒烯相比，Sc2O@C2n普遍具有更高的HOMO和LUMO能级，证明适当调控笼内团簇或可实现对于内嵌富勒烯的能级结构的调控。本项目研究通过对Sc2O@C2n碳笼结构的表征，进一步明确富勒烯碳笼以金属团簇为模板生长的机理，以及尺寸相同的碳笼之间的异构化机理。此外，我们制备了Sc2O@C82/S8以及Lu3N@C80/S8的微纳结构，结果显示它们均具有较强的光电响应特性，是一类较好的光电开关材料，其光电响应机理还在进一步研究中。在本项目资助下，我们还研究了一系列面向聚合物太阳能电池和钙钛矿太阳能电池的富勒烯受体材料，电子传输材料以及空穴传输材料，并取得了较好的器件性能。