Electro-optics of perovskite solar cells
Electro-optics of perovskite solar cells
复制标题
DOI：
10.1038/nphoton.2014.284
复制
发表时间：
2015-02-01
期刊：
影响因子：
35
通讯作者：
Meredith, Paul
中科院分区：
文献类型：
--
作者：
Lin, Qianqian;Armin, Ardalan;Meredith, Paul
有机卤化物-钙钛矿太阳能电池已成为领先的下一代光伏技术。然而，尽管效率大幅提高，但有关运作机制的许多问题仍未得到解答。在这里，我们报告了一个详细的研究，有效的CH3NH3PbI3-钙钛矿只有平面设备的电光。我们报告的介电常数在一个大的频率范围内。重要的是，我们发现静态介电常数的真实的部分类似于70，由此我们估计激子结合能为2毫电子伏，这强烈表明非激子机制。此外，Jonscher定律行为与具有离子特性的钙钛矿一致。准确了解细胞的光学常数可以改进建模和设计，并使用这些信息，我们制造了一个优化的设备，效率为16.5%。优化的器件具有类似于100%的光谱平坦的内部量子效率和最小的双分子复合。这些发现建立了系统的设计规则，以在简单的钙钛矿太阳能电池中实现类似硅的效率。
Organohalide-perovskite solar cells have emerged as a leading next-generation photovoltaic technology. However, despite surging efficiencies, many questions remain unanswered regarding the mechanisms of operation. Here we report a detailed study of the electro-optics of efficient CH3NH3PbI3-perovskite-only planar devices. We report the dielectric constants over a large frequency range. Importantly, we found the real part of the static dielectric constant to be similar to 70, from which we estimate the exciton-binding energy to be of order 2 meV, which strongly indicates a non-excitonic mechanism. Also, Jonscher's Law behaviour was consistent with the perovskite having ionic character. Accurate knowledge of the cell's optical constants allowed improved modelling and design, and using this information we fabricated an optimized device with an efficiency of 16.5%. The optimized devices have similar to 100% spectrally flat internal quantum efficiencies and minimal bimolecular recombination. These findings establish systematic design rules to achieve silicon-like efficiencies in simple perovskite solar cells.