Photoinduced Vibrations Drive Ultrafast Structural Distortion in Lead Halide Perovskite.
Photoinduced Vibrations Drive Ultrafast Structural Distortion in Lead Halide Perovskite.
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光致振动驱动卤化铅钙钛矿的超快结构畸变。
DOI：
10.1021/jacs.0c03970
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发表时间：
2020-09-30
影响因子：
15
通讯作者：
Miller RJD
中科院分区：
文献类型：
--
作者：
Duan HG;Tiwari V;Jha A;Berdiyorov GR;Akimov A;Vendrell O;Nayak PK;Snaith HJ;Thorwart M;Li Z;Madjet ME;Miller RJD
有机-无机钙钛矿在光电子学领域的成功是由各种潜在的微观现象之间复杂的相互作用决定的。假设光激发后有机阳离子和无机亚晶格的结构动力学直接影响材料的性质，从而影响器件的整体性能。在这里，我们使用超快外差探测的二维(2D)电子光谱揭示了甲基铵(MA)碘化铅钙钛矿的脉冲激发振动模式，这些模式驱动了光激发后的结构扭曲。对测量数据的振动分析使我们能够监测MA阳离子随时间演化的振动运动以及无机亚晶格的振动相干性。对观测到的振动相干态的小波分析表明，在∼300fs范围内，MA阳离子的振转运动伴随着无机骨架运动的相干演化而产生。为了使这一观察结果更加合理，我们使用了组态相互作用单分子(CIS)，它支持我们实验上观察到的MA阳离子中振子运动的相干产生，并强调了MA阳离子与无机亚晶格之间的非简谐相互作用的重要性。此外，我们的高级理论计算预测了光致振动相干从MA阳离子转移到无机亚晶格，导致晶格重组形成长寿命的极化子态。我们的研究揭示了有机阳离子和无机亚晶格在极化子形成过程中的相互作用，这可能为下一代钙钛矿型太阳能电池材料提供新的设计原则。
The success of organic–inorganic perovskites in optoelectronics is dictated by the complex interplay between various underlying microscopic phenomena. The structural dynamics of organic cations and the inorganic sublattice after photoexcitation are hypothesized to have a direct effect on the material properties, thereby affecting the overall device performance. Here, we use ultrafast heterodyne-detected two-dimensional (2D) electronic spectroscopy to reveal impulsively excited vibrational modes of methylammonium (MA) lead iodide perovskite, which drive the structural distortion after photoexcitation. Vibrational analysis of the measured data allows us to monitor the time-evolved librational motion of the MA cation along with the vibrational coherences of the inorganic sublattice. Wavelet analysis of the observed vibrational coherences reveals the coherent generation of the librational motion of the MA cation within ∼300 fs complemented with the coherent evolution of the inorganic skeletal motion. To rationalize this observation, we employed the configuration interaction singles (CIS), which support our experimental observations of the coherent generation of librational motions in the MA cation and highlight the importance of the anharmonic interaction between the MA cation and the inorganic sublattice. Moreover, our advanced theoretical calculations predict the transfer of the photoinduced vibrational coherence from the MA cation to the inorganic sublattice, leading to reorganization of the lattice to form a polaronic state with a long lifetime. Our study uncovers the interplay of the organic cation and inorganic sublattice during formation of the polaron, which may lead to novel design principles for the next generation of perovskite solar cell materials.
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影响因子：
13.6
作者：
Miyata K;Atallah TL;Zhu XY
通讯作者：
Zhu XY
影响因子：
56.9
作者：
Lee, Michael M.;Teuscher, Joel;Snaith, Henry J.
通讯作者：
Snaith, Henry J.
影响因子：
13.6
作者：
Miyata K;Meggiolaro D;Trinh MT;Joshi PP;Mosconi E;Jones SC;De Angelis F;Zhu XY
通讯作者：
Zhu XY
影响因子：
6.7
作者：
Green, Martin A.;Dunlop, Ewan D.;Ho-Baillie, Anita W. Y.
通讯作者：
Ho-Baillie, Anita W. Y.
影响因子：
2.9
作者：
Egorova, Dassia
通讯作者：
Egorova, Dassia