Yue Xingyu, Ouyang Yunfei, Zhang Zeyu, Wang Chunwei, Zu Xinzhi, Yin Qinxue, Liu Zhengzheng, Hu Zhiping, Zheng Yujie, Sun Kuan, Leng Yuxin, Du Juan
State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS), Shanghai 201800, China.
School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
J Phys Chem Lett. 2024 Sep 26;15(38):9659-9667. doi: 10.1021/acs.jpclett.4c02293. Epub 2024 Sep 16.
Organic-inorganic lead halide perovskites (OLHPs) have demonstrated exceptional properties in high-performance photoelectric devices. However, the impact of A-site cations, specifically formamidinium and methylammonium (MA), on the optoelectronic properties of OLHPs, particularly in the context of hot carrier utilization, remains a topic of debate. In this study, we propose a method for characterizing hot carrier transportation by measuring the hot carrier mobility and momentum-dependent transient photocurrent influenced by A-site cations in OLHPs. Our findings reveal that the direction of photon drag current is reversed upon substitution of the MA cation, suggesting the strong localization of hot carriers by the MA cation dipole. Furthermore, the correlation between the hot carrier photoconductivity and the electronic structure in different A-site cation samples indicates that hot carrier mobility in OLHPs can be reduced by >50% due to the influence of A-site cations.
有机-无机铅卤化物钙钛矿（OLHPs）在高性能光电器件中展现出了卓越的性能。然而，A位阳离子，特别是甲脒和甲基铵（MA），对OLHPs光电性能的影响，尤其是在热载流子利用的背景下，仍然是一个有争议的话题。在本研究中，我们提出了一种通过测量OLHPs中受A位阳离子影响的热载流子迁移率和动量相关的瞬态光电流来表征热载流子传输的方法。我们的研究结果表明，在MA阳离子被取代后，光子拖曳电流的方向发生了反转，这表明MA阳离子偶极对热载流子有很强的局域作用。此外，不同A位阳离子样品中热载流子光电导率与电子结构之间的相关性表明，由于A位阳离子的影响，OLHPs中的热载流子迁移率可降低50%以上。
