Endohedral fullerenes for organic photovoltaic devices
Endohedral fullerenes for organic photovoltaic devices
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DOI：
10.1038/nmat2379
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发表时间：
2009-03-01
期刊：
影响因子：
41.2
通讯作者：
Drees, Martin
中科院分区：
文献类型：
--
作者：
Ross, Russel B.;Cardona, Claudia M.;Drees, Martin
到目前为止，有机光伏（OPV）器件功率转换效率（PCE）的基本限制之一是由供体聚合物和受体分子之间的分子轨道失配引起的低电压输出。在这里，我们提出了一种解决低电压输出的方法，通过引入新的三金属氮化物内嵌富勒烯（TNEFs）作为受体材料用于光伏器件。TNEFs是由史蒂文森等人于1999年发现的。(1)首次合成了TNEF受体Lu（3）N@ C（80）的衍生物并将其集成到OPV器件中。Lu3N@C80的分子轨道与供体聚（3-己基）噻吩（P3 HT）的能量偏移减少，减少了电荷转移过程中的能量损失，并将开路电压（V（oc））增加到260 mV，高于用[6，6]-苯基-C（61）-丁酸甲酯（C（60）-PCBM）受体制成的参考器件。使用P3 HT作为供体材料已经观察到PCE> 4%。这项工作通过证明具有降低的供体/受体最低未占分子轨道能量偏移的OPV系统可以发生高产率电荷分离，为OPV器件中的更高PCE扫清了道路。
So far, one of the fundamental limitations of organic photovoltaic (OPV) device power conversion efficiencies (PCEs) has been the low voltage output caused by a molecular orbital mismatch between the donor polymer and acceptor molecules. Here, we present a means of addressing the low voltage output by introducing novel trimetallic nitride endohedral fullerenes (TNEFs) as acceptor materials for use in photovoltaic devices. TNEFs were discovered in 1999 by Stevenson et al.(1); for the first time derivatives of the TNEF acceptor, Lu(3)N@ C(80), are synthesized and integrated into OPV devices. The reduced energy offset of the molecular orbitals of Lu3N@ C80 to the donor, poly(3-hexyl)thiophene (P3HT), reduces energy losses in the charge transfer process and increases the open circuit voltage (V(oc)) to 260mV above reference devices made with [6,6]-phenyl-C(61)-butyric methyl ester (C(60)-PCBM) acceptor. PCEs > 4% have been observed using P3HT as the donor material. This work clears a path towards higher PCEs in OPV devices by demonstrating that high-yield charge separation can occur with OPV systems that have a reduced donor/acceptor lowest unoccupied molecular orbital energy offset.