Structure-Dependent Photoluminescence in Low-Dimensional Ethyl-, Propyl-, and Butylammonium Lead Iodide Perovskites.
Structure-Dependent Photoluminescence in Low-Dimensional Ethyl-, Propyl-, and Butylammonium Lead Iodide Perovskites.
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低维乙基、丙基和丁基铵碘化铅钙钛矿中的结构依赖性光致发光。
DOI：
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发表时间：
2019
影响因子：
9.5
通讯作者：
H. Ahn
中科院分区：
文献类型：
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作者：
Chang;Fang‐zhou Liu;Ting;Kuan;Chung‐Kai Chang;Yanling He;T. Leung;A. Ng;Chia;Jasminka Popović;A. Djurišić;H. Ahn
有机-无机复合钙钛矿作为光伏和发光器件的下一代材料引起了人们的极大关注。然而，它们的环境不稳定问题仍然是实际应用的最大挑战。最近出现的具有Ruddlesden-Popper(R-P)结构的二维(2D)钙钛矿材料被发现极大地改善了稳定性和老化问题。此外，激子在这些自然量子井结构中的强烈限制导致了在可见光谱范围内明显而狭窄的光发射，从而使光谱可调光源的发展成为可能。除了较强的准单色发射外，一些由特定的有机阳离子和无机层结构组成的二维钙钛矿结构还具有明显的宽带发射。本文报道了由单乙基铵(EA)、正丙基铵(PA)和正丁基铵(BA)这三个最短的烷基铵间隔基组成的低维钙钛矿的发光性质和降解过程。已知的是，(BA)2PbI4由由双层BA阳离子隔开的角共享的PbI6八面体组成的良好取向的2D薄膜，而具有较短的烷基链的EA倾向于形成其他类型的低维结构。然而，制备的新鲜EAPbI3、(PA)2PbI4和(BA)2PbI4的光吸收边明显蓝移到2.4-2.5 eV，与其3d对应的钙钛矿结构MAPbI3相比，它们都发出了窄的激子光致发光。此外，通过仔细优化沉积条件，我们还获得了以2D为主的(PA)2PbI4结构。然而，与(BA)2PbI4不同的是，当暴露在环境中(PA)2PbI4时，2PbI4很容易转变为不同的晶体结构，表现出从大约500 nm到800 nm的显著宽带光，并且随着结构转变的进行，强度逐渐增加。
Hybrid organic-inorganic perovskites have attracted great attention as the next generation material for photovoltaic and light emitting devices. However, their environment instability issue remains as the largest challenge for practical applications. Recently emerging two-dimensional (2D) perovskites with Ruddlesden-Popper (R-P) structures are found to greatly improve the stability and aging problems. Furthermore, strong confinement of excitons in these natural quantum-well structures results in the distinct and narrow light emission in the visible spectral range, enabling the development of spectrally tunable light sources. Besides the strong quasi-monochromatic emission, some 2D perovskites comprised of the specific organic cations and inorganic layer structures emit a pronounced broadband emission. Herein we report the light emitting properties and the degradation of low-dimensional perovskites consisting of the three shortest alkylammonium spacers, mono-ethylammonium (EA), n-propylammonium (PA), and n-butylammonium (BA). While (BA)2PbI4 is known to form well-oriented 2D thin films consisting of layers of corner-sharing PbI6 octahedra separated by a bilayer of BA cations, EA with shorter alkyl chains tends to form other type of lower dimensional structure. Nevertheless, optical absorption edges of as-prepared fresh EAPbI3, (PA)2PbI4, and (BA)2PbI4 are obviously blue-shifted to 2.4-2.5 eV compared to their 3D counterpart, methylammonium lead iodide (MAPbI3) perovskite, and they all emit narrow excitonic photoluminescence. Furthermore, by carefully optimizing deposition conditions, we have achieved predominantly 2D structure for (PA)2PbI4. However, unlike (BA)2PbI4, upon exposure to ambient environment (PA)2PbI4 readily transforms to a different crystal structure, exhibiting a prominently broadband light from ca. 500 nm to 800 nm and a gradual increase in intensity as structural transformation proceeds.
影响因子：
15
作者：
Wu, Xiaoxi;Trinh, M. Tuan;Zhu, X. -Y.
通讯作者：
Zhu, X. -Y.