平面异质结有机-无机杂化钙钛矿太阳电池研究进展

高效低成本太阳电池的研发是太阳能光伏技术大规模推广应用的关键. 近年来兴起的有机- 无机杂化钙钛矿(以下简称钙钛矿)太阳电池因具有光电能量转换效率高、制备工艺简单等优点, 引起了学术界和产业界的广泛关注, 具有广阔的发展前景. 其中平面异质结钙钛矿太阳电池因具有结构简单, 可低温制备等诸多优点, 成为目前研究的一个重要方向. 平面异质结钙钛矿太阳电池分为n-i-p型和p-i-n型两种结构. 其中钙钛矿分别与电子传输层和空穴传输层形成两个界面, 在这两个界面上实现电子和空穴的快速分离. 电子传输层和空穴传输层分别为电子和空穴提供了独立的输运通道. 平面异质结结构有利于钙钛矿太阳电池中电子和空穴的分离、传输和收集. 此外, 该结构不需要高温烧结的多孔结构氧化物骨架, 扩大了电子和空穴传输材料的选择范围. 可以根据钙钛矿材料的能带分布及载流子传输特性, 来选择能级和载流子传输速率更为匹配的传输材料. 本文对钙钛矿的材料特性, 平面异质结结构的由来及发展进行了简要的概述. 其中重点介绍了平面异质结钙钛矿太阳电池的结构特征、工作机理、钙钛矿/电荷传输层的界面特性, 以及电池性能的优化, 包括钙钛矿薄膜制备、空穴和电子传输层的优化等. 最后对钙钛矿电池的发展前景及存在问题进行了阐述, 为今后高效、稳定钙钛矿太阳电池的研究提供参考.

Recent advances in planar hetero junction organic-inorganic hybrid p erovskite solar cells

The development of highly efficient and low-cost solar cells is the key to large-scale application of solar photovoltaic technology. In recent years, the solution-processed organic-inorganic perovskite solar cells attracted considerable attention because of their advantages of high energy conversion efficiency, low cost, and ease of processing. The ambipolar semiconducting characteristic of perovskite enables the construction of planar heterojunction architecture to be possible in perovskite-based solar cells. This kind of architecture avoids the use of mesoporous metal oxide film, which simplifies the processing route and makes it easier to fabricate flexible and tandem perovskite-based solar cells. Planar heterojunction perovskite solar cells can be divided into n-i-p type and p-i-n type according to the charge flow direction. Two interfaces are formed between perovskite film and hole/electron transport layer, where efficient charge separation can be realized. Hole and electron transport layers can form separated continuous paths for the transport of holes and electrons, thus beneficial to improving exciton separation, charge transportation, and collection efficiency. In addition, this planar architecture avoids the use of high temperature sintered mesoporous metal oxide framework; this is beneficial to expanding the choice of the charge transport materials. In this paper, we review the recent progress on the planar heterojunction perovskite solar cells. First, we introduce the material properties of perovskite, the evolution of device architecture, and the working principle of p-i-n type and n-i-p type planar heterojunction perovskite solar cells. Then, we review the recent progress and optimization of planar heterojunction perovskite solar cells from every aspect of perovskite preparation and the selection of electron/hole transport materials. Finally, we would like to give a perspective view on and address the concerns about perovskite solar cells.