高效率钙钛矿太阳电池发展中的关键问题

Key issues in highly efficient perovskite solar cells

钙钛矿太阳电池的迅速发展为解决未来能源问题带来一线曙光.但是,钙钛矿太阳电池在高效率电池器件的可重现性、稳定性以及性能评估等方面还面临着很多问题,严重制约其今后的发展.本文综述了钙钛矿太阳电池面世以来发生的重要进展,以及存在的几个关键性问题.从器件基本结构和基本工作原理出发,本文重点讨论了光吸收层的光谱和形貌等性质对器件性能和可重现性的影响,阐明了电子传输层和空穴阻隔层的重要作用,论述了空穴传输层的相关进展以及其对器件稳定性的影响.通过对以上关键问题的讨论和总结,本文对钙钛矿太阳电池未来的研究发展进行了展望.

Preparation of Perovskite solar cell, an emerging low-cost photovoltaic technology in rapid development, has provided a ray of hope to solve the energy problem. However, its low reproducibility and stability limit the wide application of this potential technology. In this review, we summarize the recent progress with a focused discussion on some key issues in the development of perovskite solar cells. Starting from the analysis of basic structure and working principles, we first discuss the perovskite-based light harvesting layer and the general strategy to control its spectrum response. We also demonstrate the effect of film morphology on the device performance and the reproducibility which requires very uniform thin films. Then we discuss the major function of electron transporting layer and hole blocking layer, and point out the importance of compact hole blocking layer with less nano-scaled pinholes. For the hole transporting layer, we focus the discussion on the stability problem induced by widely used dopants that can improve the hole conductivity in the hole transporting layer while the dopants＇ deliquescent behavior also can induce the decomposition of perovskite-based light harvesting layer with a rapid degradation of the whole device. The potential approaches to solve this stability problem,such as using a dopant-free hole transporting material or making device without any hole transporting materials, are also discussed. Finally, we are in prospect of overcoming the main challenges in the future research for high performance perovskite solar cells.