Bi Dongqin, Tress Wolfgang, Dar M Ibrahim, Gao Peng, Luo Jingshan, Renevier Clémentine, Schenk Kurt, Abate Antonio, Giordano Fabrizio, Correa Baena Juan-Pablo, Decoppet Jean-David, Zakeeruddin Shaik Mohammed, Nazeeruddin Mohammad Khaja, Grätzel Michael, Hagfeldt Anders
Laboratory of Photomolecular Science, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland.
Laboratory of Photonics and Interfaces, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland.
Sci Adv. 2016 Jan 1;2(1):e1501170. doi: 10.1126/sciadv.1501170. eCollection 2016 Jan.
We report on a new metal halide perovskite photovoltaic cell that exhibits both very high solar-to-electric power-conversion efficiency and intense electroluminescence. We produce the perovskite films in a single step from a solution containing a mixture of FAI, PbI2, MABr, and PbBr2 (where FA stands for formamidinium cations and MA stands for methylammonium cations). Using mesoporous TiO2 and Spiro-OMeTAD as electron- and hole-specific contacts, respectively, we fabricate perovskite solar cells that achieve a maximum power-conversion efficiency of 20.8% for a PbI2/FAI molar ratio of 1.05 in the precursor solution. Rietveld analysis of x-ray diffraction data reveals that the excess PbI2 content incorporated into such a film is about 3 weight percent. Time-resolved photoluminescence decay measurements show that the small excess of PbI2 suppresses nonradiative charge carrier recombination. This in turn augments the external electroluminescence quantum efficiency to values of about 0.5%, a record for perovskite photovoltaics approaching that of the best silicon solar cells. Correspondingly, the open-circuit photovoltage reaches 1.18 V under AM 1.5 sunlight.
我们报道了一种新型金属卤化物钙钛矿光伏电池，它兼具非常高的太阳能到电能的转换效率和强烈的电致发光特性。我们从前体溶液中一步制备出含有FAI、PbI₂、MABr和PbBr₂混合物（其中FA代表甲脒阳离子，MA代表甲基铵阳离子）的钙钛矿薄膜。分别使用介孔TiO₂和Spiro-OMeTAD作为电子和空穴特异性接触层，我们制备出了钙钛矿太阳能电池，在前体溶液中PbI₂/FAI摩尔比为1.05时，其最大功率转换效率达到20.8%。对X射线衍射数据进行的Rietveld分析表明，掺入该薄膜中的过量PbI₂含量约为3重量百分比。时间分辨光致发光衰减测量表明，少量过量的PbI₂抑制了非辐射性电荷载流子复合。这反过来又将外部电致发光量子效率提高到约0.5%，这是钙钛矿光伏电池的一项纪录，接近最佳硅太阳能电池的水平。相应地，在AM 1.5太阳光下，开路光电压达到1.18 V。
