Hoefler Sebastian F, Trimmel Gregor, Rath Thomas
Institute for Chemistry and Technology of Materials (ICTM), NAWI Graz, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
Monatsh Chem. 2017;148(5):795-826. doi: 10.1007/s00706-017-1933-9. Epub 2017 Mar 8.
Metal halide perovskites have revolutionized the field of solution-processable photovoltaics. Within just a few years, the power conversion efficiencies of perovskite-based solar cells have been improved significantly to over 20%, which makes them now already comparably efficient to silicon-based photovoltaics. This breakthrough in solution-based photovoltaics, however, has the drawback that these high efficiencies can only be obtained with lead-based perovskites and this will arguably be a substantial hurdle for various applications of perovskite-based photovoltaics and their acceptance in society, even though the amounts of lead in the solar cells are low. This fact opened up a new research field on lead-free metal halide perovskites, which is currently remarkably vivid. We took this as incentive to review this emerging research field and discuss possible alternative elements to replace lead in metal halide perovskites and the properties of the corresponding perovskite materials based on recent theoretical and experimental studies. Up to now, tin-based perovskites turned out to be most promising in terms of power conversion efficiency; however, also the toxicity of these tin-based perovskites is argued. In the focus of the research community are other elements as well including germanium, copper, antimony, or bismuth, and the corresponding perovskite compounds are already showing promising properties.
金属卤化物钙钛矿彻底改变了可溶液加工的光伏领域。在短短几年内，基于钙钛矿的太阳能电池的功率转换效率已显著提高至超过20%，这使得它们现在与基于硅的光伏电池效率相当。然而，这种基于溶液的光伏技术的突破存在一个缺点，即只有使用基于铅的钙钛矿才能获得这些高效率，尽管太阳能电池中的铅含量很低，但这可能会成为基于钙钛矿的光伏电池各种应用及其在社会中被接受的重大障碍。这一事实开启了关于无铅金属卤化物钙钛矿的新研究领域，目前该领域非常活跃。我们以此为契机，回顾这个新兴的研究领域，并根据最近的理论和实验研究，讨论在金属卤化物钙钛矿中替代铅的可能替代元素以及相应钙钛矿材料的性能。到目前为止，就功率转换效率而言，基于锡的钙钛矿被证明是最有前途的；然而，这些基于锡的钙钛矿的毒性也存在争议。研究界关注的其他元素还包括锗、铜、锑或铋，相应的钙钛矿化合物已经显示出有前景的性能。
