Momentarily trapped exciton polaron in two-dimensional lead halide perovskites.
Momentarily trapped exciton polaron in two-dimensional lead halide perovskites.
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二维卤化铅钙钛矿中的瞬时俘获激子极化子
DOI：
10.1038/s41467-021-21721-3
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发表时间：
2021-03-03
影响因子：
16.6
通讯作者：
Zhu H
中科院分区：
文献类型：
--
作者：
Tao W;Zhang C;Zhou Q;Zhao Y;Zhu H
二维卤化铅钙钛矿具有独特的激子特征，在光电应用中显示出令人兴奋的潜力。与具有大极化子特征的三维对应物相比，由于极性晶格和软晶格，激子与声子之间的长程和短程相互作用如何定义二维钙钛矿中的激子还有待揭示。在这里，我们试图通过静态和时间分辨光谱来理解二维CsPbBr3钙钛矿中激子的性质，并进一步利用Urbach-Martienssen规则进行合理化。我们定量地展示了二维CsPbBr3中的中间激子-声子耦合，其中激子极化子被晶格振动暂时自困。在室温下，自由激子极化子与自捕获激子极化子以~ 34 meV的势垒进行0.25 ps的超快相互转换，产生具有低能量尾的本征不对称光致发光。本研究揭示了二维钙钛矿中激子极化子的复杂动态图景，并强调了调控激子-声子耦合的重要性。二维钙钛矿由于其巨大的激子结合能而显示出光电应用的潜力，但激子-声子与极性软晶格的相互作用尚未得到很好的理解。在这里，作者揭示了激子极化子被晶格振动暂时捕获的中间耦合状态。
Two-dimensional (2D) lead halide perovskites with distinct excitonic feature have shown exciting potential for optoelectronic applications. Compared to their three-dimensional counterparts with large polaron character, how the interplay between long- and short- range exciton-phonon interaction due to polar and soft lattice define the excitons in 2D perovskites is yet to be revealed. Here, we seek to understand the nature of excitons in 2D CsPbBr3 perovskites by static and time-resolved spectroscopy which is further rationalized with Urbach-Martienssen rule. We show quantitatively an intermediate exciton-phonon coupling in 2D CsPbBr3 where exciton polarons are momentarily self-trapped by lattice vibrations. The 0.25 ps ultrafast interconversion between free and self-trapped exciton polaron with a barrier of ~ 34 meV gives rise to intrinsic asymmetric photoluminescence with a low energy tail at room temperature. This study reveals a complex and dynamic picture of exciton polarons in 2D perovskites and emphasizes the importance to regulate exciton-phonon coupling. Two-dimensional perovskite shows potential for optoelectronic applications due to its large exciton binding energy, yet the exciton-phonon interaction with the polar soft lattice is not well-understood. Here, the authors reveal the intermediate coupling regime where exciton polarons are momentarily trapped by lattice vibrations.
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影响因子：
15
作者：
Ithurria, S.;Bousquet, G.;Dubertret, B.
通讯作者：
Dubertret, B.
影响因子：
15
作者：
Mao, Lingling;Guo, Peijun;Kanatzidis, Mercouri G.
通讯作者：
Kanatzidis, Mercouri G.
影响因子：
41.2
作者：
Gong, Xiwen;Voznyy, Oleksandr;Sargent, Edward H.
通讯作者：
Sargent, Edward H.
影响因子：
16.6
作者：
Guo, Yinsheng;Yaffe, Omer;Brus, Louis E.
通讯作者：
Brus, Louis E.
影响因子：
16.6
作者：
Blancon JC;Stier AV;Tsai H;Nie W;Stoumpos CC;Traoré B;Pedesseau L;Kepenekian M;Katsutani F;Noe GT;Kono J;Tretiak S;Crooker SA;Katan C;Kanatzidis MG;Crochet JJ;Even J;Mohite AD
通讯作者：
Mohite AD