Slow thermal equilibration in methylammonium lead iodide revealed by transient mid-infrared spectroscopy.
Slow thermal equilibration in methylammonium lead iodide revealed by transient mid-infrared spectroscopy.
复制标题
DOI：
10.1038/s41467-018-05015-9
复制
发表时间：
2018-07-18
影响因子：
16.6
通讯作者：
Schaller RD
中科院分区：
文献类型：
--
作者：
Guo P;Gong J;Sadasivam S;Xia Y;Song TB;Diroll BT;Stoumpos CC;Ketterson JB;Kanatzidis MG;Chan MKY;Darancet P;Xu T;Schaller RD
有机-无机杂化钙钛矿是用于廉价高效光伏和发光器件的新兴半导体。与传统的无机半导体不同，杂化钙钛矿由共存的有机和无机子晶格组成，它们具有不同的原子质量和键强度。这些不同组件的纳米级相互渗透缺乏强电子和振动耦合，对理解电荷和散热提出了根本性挑战。在这里，我们通过瞬态探测带隙以上光激发后有机子晶格的振动模式来研究甲基碘化铅（MAPbI3）中的声子布居和平衡过程。我们在数百皮秒到几纳秒的时间尺度上观察到子晶格间的热平衡。根据基于第一原理计算的双温度模型的支持，缓慢的热平衡分别归因于无机和有机子晶格的连续声子群。观察到的持久热非平衡为新兴混合材料类别的热传输和热管理提供了见解。有机-无机杂化钙钛矿是高效光伏发电的新兴材料；然而，了解材料内部的电荷/热量如何消散仍然是一个挑战。在这里，作者使用光谱方法观察有机和无机成分之间异常缓慢的热平衡。
Hybrid organic–inorganic perovskites are emerging semiconductors for cheap and efficient photovoltaics and light-emitting devices. Different from conventional inorganic semiconductors, hybrid perovskites consist of coexisting organic and inorganic sub-lattices, which present disparate atomic masses and bond strengths. The nanoscopic interpenetration of these disparate components, which lack strong electronic and vibrational coupling, presents fundamental challenges to the understanding of charge and heat dissipation. Here we study phonon population and equilibration processes in methylammonium lead iodide (MAPbI3) by transiently probing the vibrational modes of the organic sub-lattice following above-bandgap optical excitation. We observe inter-sub-lattice thermal equilibration on timescales ranging from hundreds of picoseconds to a couple of nanoseconds. As supported by a two-temperature model based on first-principles calculations, the slow thermal equilibration is attributable to the sequential phonon populations of the inorganic and organic sub-lattices, respectively. The observed long-lasting thermal non-equilibrium offers insights into thermal transport and heat management of the emergent hybrid material class. Hybrid organic-inorganic perovskites are emerging materials for efficient photovoltaics; however understanding how charge/heat dissipates inside the material remains a challenge. Here, the authors use a spectroscopic approach to observe unusually slow thermal equilibration between the organic and inorganic components.
登录
查看更多内容
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：
5.7
作者：
Glaser, Tobias;Mueller, Christian;Lovrincic, Robert
通讯作者：
Lovrincic, Robert
影响因子：
6.4
作者：
Hills-Kimball, K.;Nagaoka, Y.;Chen, O.
通讯作者：
Chen, O.
影响因子：
10.8
作者：
Hata, Tomoyuki;Giorgi, Giacomo;Yamashita, Koichi
通讯作者：
Yamashita, Koichi
影响因子：
35
作者：
Manser, Joseph S.;Kamat, Prashant V.
通讯作者：
Kamat, Prashant V.