Progress on perovskite-based solar cells

As an important kind of clean and renewable energy source, solar cells are attracting more and more attention in recent years due to their great potential in addressing the energy crisis issues. In this context, developing novel solar cells with both high power conversion efficiency and low cost is becoming a hot research topic worldwide. In 2009, CH3NH3PbI3 and CH3NH3PbBr3 were firstly fabricated as quantum dot and used in dye-sensitized solar cell (DSSC) with a power conversion efficiency of 3.8%. Since then, many fascinating breakthroughs on perovskite-based solar cells have been achieved in an amazing speed, especially in recent 5 years. The overall performance of perovskite-based solar cells has outperformed several other types of traditional solar cells. Due to the importance of perovskite-based solar cells, the related research has been elected as one of the top 10 scientific breakthroughs in 2013 by Science magazine. So far, a high power conversion efficiency up to 20.1% has been reported by Korea Research Institute of Chemical Technology (KRICT). The perovskite-based solar cells are with low cost and easy to be fabricated. Based on their excellent properties, such as good optical absorption and high charge transfer efficiency, breakthroughs on much higher power conversion efficiencies can be expected in the future. Here we summarize some state-of-the-art research advances on perovskite-based solar cells achieved from 2014 to now. We focus on the basics of perovskite-based solar cells, interface control, synthesis routes, etc. Current strategies for improving the power conversion efficiency, stability and eco-friendliness are summarized. Moreover, we propose the challenges that need to be overcome in the near future. Firstly, the working mechanism of those high efficiency solar cells is still an open question. Secondly, how to improve both the power conversion efficiency and the stability is still a big challenge. The perovskite-based solar cells are actually very sensitive to the ambient water vapor and oxygen. Thirdly, the large-area mass production of perovskite-based solar cells has not been realized so far. The size of the perovskite-based solar cell devices obtained in the laboratory scale is only several centimeters, which can not meet the industrial production demand. Finally, how to avoid using heavy metals, such as Pb, and keep the high power conversion efficiency as well, is also a big challenge. In the future, perovskite solar cells are supposed to be lead-free without sacrificing their high efficiency. © 2016, Science Press. All right reserved.