Department of Chemistry, Bar Ilan University, 52900 Ramat-Gan, Israel.
Phys Chem Chem Phys. 2013 Mar 21;15(11):3841-5. doi: 10.1039/c3cp44719g.
Quantum dot sensitized solar cells (QDSSCs) present a promising technology for next generation photovoltaic cells, having exhibited a considerable leap in performance over the last few years. However, recombination processes occurring in parallel at the TiO(2)-QDs-electrolyte triple junction constitute one of the major limitations for further improvement of QDSSCs. Reaching higher conversion efficiencies necessitates gaining a better understanding of the mechanisms of charge recombination in these kinds of cells; this will essentially lead to the development of new solutions for inhibiting the described losses. In this study we have systematically examined the contribution of each interface formed at the triple junction to the recombination of the solar cell. We show that the recombination of electrons at the TiO(2)/QDs interface is as important as the recombination from TiO(2) and QDs to the electrolyte. By applying conformal MgO coating both above and below the QD surface, recombination rates were significantly reduced, and an improvement of more than 20% in cell efficiency was recorded.
量子点敏化太阳能电池（QDSSCs）为下一代光伏电池提供了一种很有前途的技术，在过去几年中，其性能有了相当大的飞跃。然而，在 TiO(2)-QDs-电解质三结处同时发生的复合过程是进一步提高 QDSSCs 性能的主要限制因素之一。要达到更高的转换效率，就需要更好地了解这些电池中电荷复合的机制；这将从本质上为抑制所描述的损耗开发新的解决方案。在这项研究中，我们系统地研究了在三结处形成的每个界面对太阳能电池复合的贡献。我们表明，TiO(2)/QDs 界面处电子的复合与 TiO(2)和 QDs 到电解质的复合一样重要。通过在 QD 表面上下施加共形 MgO 涂层，复合速率显著降低，并且记录到电池效率提高了 20%以上。
