2Dorganic–inorganichybridperovskites (OIHPs) represent a unique class of materials with a natural quantum‐well structure and quasi‐2D electronic properties. Here, a versatile direct solution‐based synthesis of mono‐ and few‐layer OIHP nanosheets and a systematic study of their electronic structure as a function of the number of monolayers by photoluminescence and absorption spectroscopy are reported
二维有机-无机杂化钙钛矿(OIHP)代表一类独特的材料,具有天然的量子阱结构和准2D电子性质。在这里,报道了一种基于直接溶液的多功能单层和多层OIHP纳米片的合成方法,并通过光致发光和吸收光谱系统研究了它们的电子结构与单层数的关系。发现各种OIHP的单层具有高电子质量,高量子产率和可忽略的斯托克斯位移证明了这一点。结果表明,当层厚度从体层减小到单层时,地面激子峰蓝移约40 meV。还表明,对于(C 6 H 5(CH 2),激子结合能实际上保持不变2 NH 3)2 PbI 4具有层数。与以前的报告相比,(C 4 H 9 NH 3)2 PbI 4观察到相似的趋势。此外,发现光致发光寿命随着单层数量的减少而减少,这表明表面陷阱态在电子-空穴对的非辐射复合中起着主导作用。
Dynamic Motion of Organic Spacer Cations in Ruddlesden–Popper Lead Iodide Perovskites Probed by Solid-State NMR Spectroscopy
作者:Clayton J. Dahlman、Rhiannon M. Kennard、Piotr Paluch、Naveen R. Venkatesan、Michael L. Chabinyc、G. N. Manjunatha Reddy
DOI:10.1021/acs.chemmater.0c03958
日期:2021.1.26
structures of linear alkylammonium and aromatic spacers in lead iodide RP phases (n = 1) are characterized at ambient temperatures using solid-state NMR (ssNMR) spectroscopy and compared with previously reported crystal structures derived from X-ray diffraction. Rigid and flexible sites of spacers are distinguished by examining 13C1H} and 15N1H} cross-polarization magic-angle spinning (CP-MAS) signal intensity
层状杂化有机-无机钙钛矿,例如卤化铅Ruddlesden-Popper(RP)系列,是可溶液处理的二维(2D)材料,具有可调的光电特性。离子钙钛矿亚结构和有机间隔物阳离子之间的动态相互作用会影响与器件应用相关的光电性能。在此,在室温下使用固态NMR(ssNMR)光谱对碘化铅RP相(n = 1)中线性烷基铵和芳族间隔基的静态和动态结构进行了表征,并与先前报道的从X射线衍射得出的晶体结构进行了比较。通过检查13 C 1 H}和15 N 1H}交叉极化幻角旋转(CP-MAS)信号强度建立。对于短和长烷基铵间隔基,观察到特定位置刚性的不同趋势。短间隔基(例如丁基铵)通过强亲和力相互作用与碘化铅八面体相连,而更长的间隔基(例如十二烷基铵)在RP中间层中比在八面体表面附近更坚硬。苯乙铵和丁铵间隔基的刚性相似,我们估计到2D 13时,苯环的局部重取向时间范围为10–100μs。C CP变量接触(
ISOMERIZATION OF EPOXYALKENES TO 2,5-DIHYDROFURANS AND CATALYSTS COMPOSITIONS USEFUL THEREFOR
申请人:EASTMAN KODAK COMPANY
公开号:EP0518973A1
公开(公告)日:1992-12-23
[EN] ISOMERIZATION OF EPOXYALKENES TO 2,5-DIHYDROFURANS AND CATALYSTS COMPOSITIONS USEFUL THEREFOR
申请人:EASTMAN KODAK COMPANY
公开号:WO1991013882A1
公开(公告)日:1991-09-19
(EN) Disclosed are processes for the isomerization of epoxyalkenes to dihydrofurans by contacting an epoxyalkene with a catalyst comprising a quaternary organic onium iodide compounds, optionally deposited on a non-acidic support and/or in combination with a Lewis acid co-catalyst. The catalyst may comprise a supported catalyst, an unsupported catalyst or a solution of the catalytically-active components in an inert, organic solvent.(FR) Procédés d'isomérisation d'époxyalcènes en dihydrofurannes, selon lesquels l'époxyalcène est contacté par un catalyseur comprenant un composé organique quaternaire de iodure d'onium déposé facultativement sur un support non acidifère et/ou utilisé en combinaison avec un co-catalyseur à l'acide de Lewis. Le catalyseur peut comporter un catalyseur supporté, un catalyseur non supporté ou une solution de composants catalytiquement actifs dans un solvant organique inerte.
[CH<sub>3</sub>(CH<sub>2</sub>)<sub>11</sub>NH<sub>3</sub>]SnI<sub>3</sub>: A Hybrid Semiconductor with MoO<sub>3</sub>-type Tin(II) Iodide Layers
作者:Zhengtao Xu、David B. Mitzi
DOI:10.1021/ic0347081
日期:2003.10.1
with that of the well-studied SnI(4)(2)(-)-based perovskite semiconductors, such as [CH(3)(CH(2))(11)NH(3)](2)SnI(4), with a red-shifted and broadened exciton peak associated with the bandgap, apparently due to the increased dimensionality of the Sn-I framework. The title compound offers, aside from the hybrid perovskites, a new type of solution-processable Sn-I network for potential applications in semiconductive