Li Junwen, Haney Paul M
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA; Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA.
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Appl Phys Lett. 2016 Nov;109(19). doi: 10.1063/1.4967176.
We study the circular photogalvanic effect in the organometal halide perovskite solar cell absorber CHNHPbI. The calculated photocurrent density for a system with broken inversion symmetry is about 10 A/W, comparable to the previously studied quantum well and bulk Rashba systems. The circular photogalvanic effect relies on inversion symmetry breaking, so that by tuning the optical penetration depth, the degree of inversion symmetry breaking can be probed at different depths from the sample surface. We propose that measurements of this effect may clarify the presence or absence of inversion symmetry, which remains a controversial issue and has been argued to play an important role in the high conversion efficiency of this material.
我们研究了有机金属卤化物钙钛矿太阳能电池吸收体CHNHPbI中的圆光电电流效应。对于具有破缺反演对称性的系统，计算得到的光电流密度约为10 A/W，与之前研究的量子阱和体Rashba系统相当。圆光电电流效应依赖于反演对称性的破缺，因此通过调节光穿透深度，可以在距样品表面不同深度处探测反演对称性破缺的程度。我们提出，对这种效应的测量可能会澄清反演对称性的存在与否，这仍然是一个有争议的问题，并且有人认为它在这种材料的高转换效率中起着重要作用。
