Maiti Sourav, Ferro Silvia, Poonia Deepika, Ehrler Bruno, Kinge Sachin, Siebbeles Laurens D A
Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands.
Center for Nanophotonics, AMOLF, Science Park 104, Amsterdam, The Netherlands.
J Phys Chem Lett. 2020 Aug 6;11(15):6146-6149. doi: 10.1021/acs.jpclett.0c01788. Epub 2020 Jul 20.
Carrier multiplication (CM) generates multiple electron-hole pairs in a semiconductor from a single absorbed photon with energy exceeding twice the band gap. Thus, CM provides a promising way to circumvent the Shockley-Queisser limit of solar cells. The ideal material for CM should have significant overlap with the solar spectrum and should be able to fully utilize the excess energy above the band gap for additional charge carrier generation. We report efficient CM in mixed Sn/Pb halide perovskites (band gap of 1.28 eV) with onset just above twice the band gap. The CM rate outcompetes the carrier cooling process leading to efficient CM with a quantum yield of 2 for photoexcitation at 2.8 times the band gap. Such efficient CM characteristics add to the many advantageous properties of mixed Sn/Pb metal halide perovskites for photovoltaic applications.
载流子倍增（CM）在半导体中，由单个吸收光子产生多个电子 - 空穴对，该光子能量超过带隙的两倍。因此，载流子倍增为规避太阳能电池的肖克利 - 奎塞尔极限提供了一种有前景的方法。用于载流子倍增的理想材料应与太阳光谱有显著重叠，并且应能够充分利用带隙以上的多余能量来产生额外的电荷载流子。我们报道了在混合锡/铅卤化物钙钛矿（带隙为1.28电子伏特）中实现了高效的载流子倍增，其起始点刚好高于带隙的两倍。载流子倍增速率超过了载流子冷却过程，从而在带隙2.8倍的光激发下实现了量子产率为2的高效载流子倍增。这种高效的载流子倍增特性增添了混合锡/铅金属卤化物钙钛矿在光伏应用中的许多有利特性。
