Yin Jun, Naphade Rounak, Maity Partha, Gutiérrez-Arzaluz Luis, Almalawi Dhaifallah, Roqan Iman S, Brédas Jean-Luc, Bakr Osman M, Mohammed Omar F
Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia.
KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia.
Nat Commun. 2021 Jun 28;12(1):3995. doi: 10.1038/s41467-021-24258-7.
Hot-carrier cooling processes of perovskite materials are typically described by a single parabolic band model that includes the effects of carrier-phonon scattering, hot phonon bottleneck, and Auger heating. However, little is known (if anything) about the cooling processes in which the spin-degenerate parabolic band splits into two spin-polarized bands, i.e., the Rashba band splitting effect. Here, we investigated the hot-carrier cooling processes for two slightly different compositions of two-dimensional Dion-Jacobson hybrid perovskites, namely, (3AMP)PbI and (4AMP)PbI (3AMP = 3-(aminomethyl)piperidinium; 4AMP = 4-(aminomethyl)piperidinium), using a combination of ultrafast transient absorption spectroscopy and first-principles calculations. In (4AMP)PbI, upon Rashba band splitting, the spin-dependent scattering of hot electrons is responsible for accelerating hot-carrier cooling at longer delays. Importantly, the hot-carrier cooling of (4AMP)PbI can be extended by manipulating the spin state of the hot carriers. Our findings suggest a new approach for prolonging hot-carrier cooling in hybrid perovskites, which is conducive to further improving the performance of hot-carrier-based optoelectronic and spintronic devices.
钙钛矿材料的热载流子冷却过程通常用单抛物线带模型来描述，该模型包括载流子-声子散射、热声子瓶颈和俄歇加热的影响。然而，对于自旋简并抛物线带分裂成两个自旋极化带的冷却过程，即 Rashba 能带分裂效应，人们了解甚少（如果有的话）。在这里，我们结合超快瞬态吸收光谱和第一性原理计算，研究了两种稍有不同组成的二维 Dion-Jacobson 杂化钙钛矿，即(3AMP)PbI 和(4AMP)PbI（3AMP = 3-(氨甲基)哌啶鎓；4AMP = 4-(氨甲基)哌啶鎓）的热载流子冷却过程。在(4AMP)PbI 中，Rashba 能带分裂后，热电子的自旋相关散射在较长延迟时加速了热载流子冷却。重要的是，(4AMP)PbI 的热载流子冷却可以通过操纵热载流子的自旋态来延长。我们的研究结果提出了一种延长杂化钙钛矿中热载流子冷却的新方法，这有利于进一步提高基于热载流子的光电器件和自旋电子器件的性能。
