Huang Po-Jung, Taniguchi Kouji, Shigefuji Masato, Kobayashi Takatsugu, Matsubara Masakazu, Sasagawa Takao, Sato Hiroyasu, Miyasaka Hitoshi
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan.
Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.
Adv Mater. 2021 Apr;33(17):e2008611. doi: 10.1002/adma.202008611. Epub 2021 Mar 23.
The control of the optoelectronic properties of 2D organic-inorganic hybrid perovskite (2D-OIHP) lead halides is an increasingly prevalent topic. Herein, the observation of the circular photogalvanic effect (CPGE) in new enantiomorphic 2D-OIHP lead iodides is reported, which are synthesized as a first OIHP-related system belonging to a chiral space group by incorporating organic chiral cations into the inorganic layers of lead iodides. The CPGE is an optoelectronic phenomenon associated with the spin-orbit coupling of heavy atoms in noncentrosymmetric systems. Owing to the CPGE, light-helicity-dependent steady photocurrents are generated without an external bias voltage under the irradiation of circularly polarized light. Furthermore, the sign reversal of the CPGE photocurrent depending on the chirality of the designed 2D-OIHP lead iodides is observed. This result indicates formation of the theoretically predicted radial spin-polarized texture in k-space of chiral systems owing to spin-momentum locking. Hence, chiral 2D-OIHP lead halides can be a promising platform for engineering opto-spintronic functionalities.
二维有机-无机杂化钙钛矿（2D-OIHP）铅卤化物的光电性质控制是一个日益普遍的话题。在此，报道了在新型对映体二维OIHP碘化铅中观察到的圆光电流效应（CPGE），通过将有机手性阳离子掺入碘化铅的无机层中，合成了首个属于手性空间群的OIHP相关体系。CPGE是一种与非中心对称系统中重原子的自旋-轨道耦合相关的光电现象。由于CPGE，在圆偏振光照射下，无需外部偏置电压即可产生依赖于光螺旋度的稳定光电流。此外，观察到CPGE光电流的符号反转取决于所设计的二维OIHP碘化铅的手性。该结果表明，由于自旋-动量锁定，在手性系统的k空间中形成了理论预测的径向自旋极化纹理。因此，手性二维OIHP铅卤化物有望成为设计光自旋电子功能的平台。
