Efficient and Stable Solution-Processed Planar Perovskite Solar Cells
Efficient and Stable Solution-Processed Planar Perovskite Solar Cells
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发表时间：
2015-02
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通讯作者：
Chuanjiang Qin
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作者：
Chuanjiang Qin
有机-无机杂化卤化物钙钛矿是一类有趣的材料，具有优异的半导体性能，在太阳能电池、水光解、发光二极管和放大同步发射等许多领域都有很好的应用前景。自2009年Miyasaka及其同事首次发表以来，钙钛矿太阳能电池（PSCs）的功率转换效率迅速提高到20%以上。到目前为止，设备寿命仍然很短，这是所有研究人员面临的关键问题。深入了解其耐久性和降解机理对未来的应用具有重要意义和必要。在此，我们系统地研究了聚碳酸酯的结晶、形貌、器件结构、效率和耐用性之间的关系。结果，我们获得了结晶良好且覆盖完全的钙钛矿层（图1），不仅提高了功率转换效率，而且提高了长时间的耐用性。与广泛使用的氟化锂/铝对电极相比，基于金电极的PSCs由于较少的化学降解和界面变化而具有更好的耐用性，这一点通过吸收和x射线衍射光谱，外量子效率谱以及电阻抗谱得到了证明。最后，通过改进器件封装和优化器件结构，实现了具有优异耐用性的平面PSC。在环境环境（45±5℃，40±5%相对湿度）下，在太阳光（AM 1.5G, 100 mW cm）照射1000 h后，该PSC的转换效率保持在90%以上。
Organic-inorganic hybrid halide perovskites are an interesting class of materials that have excellent semiconductor properties, and demonstrated promising applications on many fields, such as solar cells, water photolysis, light emitting diodes, and amplified simutannous emission. The power conversion efficiency of perovskite solar cells (PSCs) have rapidly increased to more than 20% since first publication by Miyasaka and co-workers in 2009. So far, the device lifetime is still short, this is key issue faced for all researchers in this field. The deep understanding of their durability and degradation mechanism are important and necessary toward future applications. Herein, we systematically studied the relationship between crystallization, morphology, device structure, efficiency and durability of PSCs. As the results, we obtained the well crystalized and fully covered perovskite layer (Figure 1), which improves not only power conversion efficiency but also long-time durability. Compared to a widely used lithium fluoride/aluminum counter electrode, gold electrode-based PSCs demonstrated better durability owing to less chemical degradation and interface changing, which were proved by absorption and X-ray diffraction spectroscopy, external quantum efficiency spectra, as well as electrical impedance spectroscopy. Finally, we realized a planar PSC with excellent durability by improving device encapsulation and optimizing device structures. The conversion efficiency of this PSC could keep more than 90% of the original value after 1000 h exposure under solar light (AM 1.5G, 100 mW cm) in the ambient atmosphere (45 ± 5 °C, 40 ± 5 % relative humidity).