层状有机-无机杂化钙钛矿(C7H12N2)PbBr4的合成、结构及发光性质

通过向杂化体系中引入特殊的有机配体2-（2-氨基乙基）吡啶,利用溶液冷却技术,合成了一种二维层状有机-无机杂化钙钛矿结构材料的化合物(C7H12N2)PbBr4的晶体。 X射线单晶衍射结果表明,化合物(C7H12N2)PbBr4的单晶结构属于正交晶系,Pbca空间群,a=1.702 3 nm,b=0.828 9 nm,c=2.022 4 nm,Z=8。 无机部分是由共顶点的PbBr6金属卤化物八面体组成的二维平面片层。 采用了相对扭曲构型的有机胺阳离子与二维无机片层通过氢键作用组成了杂化钙钛矿结构。 对其光学性质进行了测试。荧光光谱的特征发射峰出现在422 nm处。     

杂化钙钛矿(NH_3C_6H_(12)NH_3)CuCl_4的制备与表征

采用低温溶液法合成了含有二铵阳离子结构的新型二维层状结构的有机/无机杂化钙钛矿材料(NH_3C_6H_(12)NH_3)CuCl_4。采用元素分析、红外光谱、X射线衍射和紫外-可见光吸收光谱等手段对其结构与性能进行了表征。结果表明该材料的紫外-可见吸收光谱吸收峰位于285 nm和387 nm,层间距为1.18 nm。二铵阳离子的引入,使有机层~+NH_3C_6H_(12)NH_3~+与2个相邻的无机框架Cu Cl42-分别通过较强的氢键结合在一起,排列更为规整,热稳定性更高。与单铵阳离子结构的杂化钙钛矿材料相比,由于不存在两层有机分子层间较弱的范德华力,(NH_3C_6H_(12)NH_3)CuCl_4材料的电阻率为1.36×105Ω·cm,比单胺结构的杂化钙钛矿材料的电阻率低3个数量级。     

可溶液加工的有机-无机杂化钙钛矿:超越光伏应用的“梦幻”材料

有机-无机杂化钙钛矿材料是可通过溶液工艺低温制备得到的直接带隙半导体晶体薄膜.在众多可溶液加工的半导体材料中,有机-无机杂化钙钛矿薄膜是为数不多的低缺陷密度、双极子传输性能优异的晶体薄膜,同时兼具宽光谱吸收和长载流子扩散距离等特性,是平面异质结太阳能电池的理想选择.另外,作为低缺陷密度的直接带隙半导体晶体材料,杂化钙钛矿薄膜具有优异的发光特性.其发光波长可通过能带工程(在分子水平上改变其组分)进行调节,因此有望在发光二极管和激光等光电器件中得到新应用.总结了钙钛矿材料的优异特性和目前应用研究的进展,并对其未来发展做了展望.     

新型有机-无机杂化钙钛矿发光材料的研究进展

作为近几年来光伏领域最具竞争力的材料之一,有机-无机杂化钙钛矿受到了广泛的重视。除了在光伏领域的潜在应用,钙钛矿材料也显示出了独特的光致发光与电致发光特性。本综述回顾了近期有机-无机杂化钙钛矿材料的快速发展历程,详细介绍了其在发光领域的研究进展与应用前景;概括了钙钛矿发光材料的特性及影响因素、发光原理、光谱可调节性,重点介绍了形貌对钙钛矿发光性能的影响;进而探讨了钙钛矿材料在发光二极管、激光器件以及发光场效应晶体管领域最新的应用进展。最后,展望了钙钛矿材料的关键性热点问题以及所面临的挑战,并尝试给未来钙钛矿材料的商业化途径指出方向。     

杂化钙钛矿光伏材料的合成及热稳定性研究——推荐一个综合化学实验

介绍了一个综合性化学实验,内容包括一步溶液法制备有机-无机杂化钙钛矿光伏材料、材料结构与形貌表征、吸光系数测定及热稳定性研究。     

手性钙钛矿纳米材料的构筑及光电性能

金属卤化物钙钛矿纳米材料因其丰富的化学结构和优异的光电性能,已成为一种极具应用前景的半导体材料。在钙钛矿无机框架中引入有机手性分子后,能够比较容易地得到手性钙钛矿纳米材料,从而可以极大地推动智能光电材料和自旋电子器件的快速发展。本文将综述手性钙钛矿纳米材料的构筑与手性产生机理的最新研究进展,包括一维手性钙钛矿纳米线、二维及准二维手性有机-无机杂化钙钛矿纳米片、三维手性钙钛矿纳米晶、超分子组装体系中诱导的手性钙钛矿纳米晶等。值得注意的是,不同种类的手性钙钛矿纳米材料在圆二色性、圆偏振发光、铁电性、自旋电子学等方面展现出优异的光电性能及巨大的应用前景。但是,有关手性钙钛矿纳米材料的研究目前还处于初级阶段,其中很多机理还存在争议,许多基础性和应用型的工作也有待开展。     

双硫腙后处理诱导的钙钛矿膜二次结晶和钝化

有机-无机杂化钙钛矿较低的缺陷形成能和表面的悬挂键会导致其薄膜中产生铅缺陷。这些深能级缺陷会直接引起载流子的非辐射复合,导致有机-无机杂化钙钛矿光伏器件的界面接触和载流子传输效率变差,最终降低了器件的综合性能。采用双硫腙作为钙钛矿薄膜表面的二次结晶诱导剂和铅缺陷钝化剂,通过对钙钛矿膜进行后处理的方法实现对钙钛矿薄膜的形貌调控和缺陷钝化。进一步的研究结果表明,双硫腙通过与铅离子配位的方式有效地钝化了铅缺陷,并诱导了表面钙钛矿晶体的二次结晶,改善了薄膜质量,进而提高了器件的综合性能。     

Li_(0.025)Na_(0.975)NbO_3低温铁电相变及晶体结构

铁电体是重要的物理器件材料之一,它们的自发极化性能在许多器件中得到广泛的应用。而铁电体中的顺电-铁电和铁电-铁电相变是一类重要的结构相变,研究这些相变,一方面可以获得产生铁电性微观机构的重要信息,另一方面对研制新的铁电材料及改进性能也有指导意义。低温铁电相变及共与晶体结构的关系是其中一个重要的分支。由于体系的复杂性及技术上难度的局限,迄今为止只有英国的Megaw等开展了这方面的研究。     

杂化钙钛矿(NH3C6H12NH3)CuCl4的制备与表征

采用低温溶液法合成了含有二铵阳离子结构的新型二维层状结构的有机/无机杂化钙钛矿材料（NH₃C₆H₁₂NH₃） CuCl₄。采用元素分析、红外光谱、X射线衍射和紫外-可见光吸收光谱等手段对其结构与性能进行了表征。结果表明该材料的紫外-可见吸收光谱吸收峰位于285 nm和387 nm,层间距为1.18 nm。二铵阳离子的引入,使有机层⁺NH₃C₆H₁₂NH₃+与2个相邻的无机框架CuCl₄^2-分别通过较强的氢键结合在一起,排列更为规整,热稳定性更高。与单铵阳离子结构的杂化钙钛矿材料相比,由于不存在两层有机分子层间较弱的范德华力,（NH₃C₆H₁₂NH₃） CuCl₄材料的电阻率为1.36×10⁵ Ω·cm,比单胺结构的杂化钙钛矿材料的电阻率低3个数量级。     

手性钙钛矿的结构维度与光电特性

近十年,有机无机杂化钙钛矿凭借其新颖优异的光电特性而引起广泛关注。最近,手性钙钛矿由于结合了钙钛矿材料和手性材料各自独特性能,在三维显示、光学信息处理、量子光学、生物探测、自旋电子等方面具有重要应用价值。根据有机、无机组分的空间分布,可以对手性钙钛矿的结构维度进行分类。本文以手性钙钛矿的不同结构维度为出发点,分别阐述了一维、二维和三维手性钙钛矿的晶体结构、光学和光电特性,包括圆二色性、圆偏振光致发光和光电探测等特性。考虑到二维手性钙钛矿具有独特的范德华层状晶体结构,重点介绍了其与其它二维材料组合成二维异质结构方面的工作。最后,分别从材料制备和器件应用的角度,总结了手性钙钛矿的重点挑战问题和未来发展方向。     

A Three-Dimensional M3AB-Type Hybrid Organic–Inorganic Antiperovskite Ferroelectric: [C3H7FN]3[SnCl6]Cl

Since the first perovskite CaTiO₃ was discovered in 1839, the development of perovskite has a history of 180 years. The emergence of solar cells (CH₃NH₃)PbI₃ has set off the trend of hybrid organic–inorganic perovskite (HOIP) materials. Since then, various HOIPs have sprung up and been widely used in various material devices. Among them, HOIP ferroelectrics have gained widespread attention. However, antiperovskite, as a twin brother of perovskite, has been neglected although it has similar structure with perovskite. Here, we successfully found that [C₃H₇FN]₃[SnCl₆]Cl has a three-dimensional (3D) antiperovskite structure with the formula M₃AB. Importantly, the compound exhibits obvious ferroelectric properties with an Aizu notation of 622F6 at 391 K. To the best of our knowledge, this is the first 3D hybrid organic–inorganic antiperovskite ferroelectric, which will greatly promote the development of antiperovskite families with more superior physical properties.     

Rapid development in two-dimensional layered perovskite materials and their application in solar cells

This review summarized recent research progresses of two-dimensional layered organic-inorganic hybrid perovskite materials and their photovoltaic performances in 2D perovskite solar cells.     

Metal-organic complex ferroelectrics

Ferroelectric materials are of importance and interest in both fundamental scientific research and various technological applications. Metal-organic complexes (MOCs) represent a class of molecule-based ferroelectrics, which have shown various properties or functionalities due to their hybrid inorganic-organic nature. This tutorial review shows the recent development of the MOC ferroelectrics with particular emphases on the mechanism of ferroelectric-to-paraelectric phase transition, symmetry consideration, and multifunctionality.     

Exploiting the Bulk Photovoltaic Effect in a 2D Trilayered Hybrid Ferroelectric for Highly Sensitive Polarized Light Detection

Polarized light detection is attracting increasing attention for its wide applications ranging from optical switches to high‐resolution photodetectors. Two‐dimensional (2D) hybrid perovskite‐type ferroelectrics combining inherent light polarization dependence of bulk photovoltaic effect (BPVE) with excellent semiconducting performance present significant possibilities. Now, the BPVE‐driven highly sensitive polarized light detection in a 2D trilayered hybrid perovskite ferroelectric, (allyammonium)₂(ethylammonium)₂Pb₃Br₁₀ ( 1 ), is presented. It shows a superior BPVE with near‐band gap photovoltage of ca. 2.5 V and high on/off switching ratio of current (ca. 10⁴). Driven by the superior BPVE, 1 exhibits highly sensitive polarized light detection with a polarization ratio as high as ca. 15, which is far more beyond than those of structural anisotropy‐based monocomponent devices. This is the first realization of BPVE‐driven polarized light detection in hybrid perovskite ferroelectrics.     

Benign‐by‐Design Solventless Mechanochemical Synthesis of Three‐, Two‐, and One‐Dimensional Hybrid Perovskites

Organic–inorganic hybrid perovskites have attracted significant attention owing to their extraordinary optoelectronic properties with applications in the fields of solar energy, lighting, photodetectors, and lasers. The rational design of these hybrid materials is a key factor in the optimization of their performance in perovskite‐based devices. Herein, a mechanochemical approach is proposed as a highly efficient, simple, and reproducible method for the preparation of four types of hybrid perovskites, which were obtained in large amounts as polycrystalline powders with high purity and excellent optoelectronics properties. Two archetypal three‐dimensional (3D) perovskites (MAPbI₃ and FAPbI₃) were synthesized, together with a bidimensional (2D) perovskite (Gua₂PbI₄) and a “double‐chain” one‐dimensional (1D) perovskite (GuaPbI₃), whose structure was elucidated by X‐ray diffraction.     

Exploring a Lead‐free Semiconducting Hybrid Ferroelectric with a Zero‐Dimensional Perovskite‐like Structure

Perovskite lead halides (CH₃NH₃PbI₃) have recently taken a promising position in photovoltaics and optoelectronics because of remarkable semiconducting properties and possible ferroelectricity. However, the potential toxicity of lead arouses great environmental concern for widespread application. A new chemically tailored lead‐free semiconducting hybrid ferroelectric is reported, N‐methylpyrrolidinium)₃Sb₂Br₉ ( 1 ), which consists of a zero‐dimensional (0‐D) perovskite‐like anionic framework connected by corner‐ sharing SbBr₆ coordinated octahedra. It presents a large ferroelectric spontaneous polarization of approximately 7.6 μC cm^?2, as well as notable semiconducting properties, including positive temperature‐dependent conductivity and ultraviolet‐sensitive photoconductivity. Theoretical analysis of electronic structure and energy gap discloses a dominant contribution of the 0‐D perovskite‐like structure to the semiconducting properties of the material. This finding throws light on the rational design of new perovskite‐like hybrids, especially lead‐free semiconducting ferroelectrics.     

Tailored Engineering of an Unusual (C4H9NH3)2(CH3NH3)2Pb3Br10 Two‐Dimensional Multilayered Perovskite Ferroelectric for a High‐Performance Photodetector

Two‐dimensional (2D) layered hybrid perovskites have shown great potential in optoelectronics, owing to their unique physical attributes. However, 2D hybrid perovskite ferroelectrics remain rare. The first hybrid ferroelectric with unusual 2D multilayered perovskite framework, (C₄H₉NH₃)₂(CH₃NH₃)₂Pb₃Br₁₀ ( 1 ), has been constructed by tailored alloying of the mixed organic cations into 3D prototype of CH₃NH₃PbBr₃. Ferroelectricity is created through molecular reorientation and synergic ordering of organic moieties, which are unprecedented for the known 2D multilayered hybrid perovskites. Single‐crystal photodetectors of 1 exhibit fascinating performances, including extremely low dark currents (ca. 10⁻¹² A), large on/off current ratios (ca. 2.5×10³), and very fast response rate (ca. 150 μs). These merits are superior to integrated detectors of other 2D perovskites, and compete with the most active CH₃NH₃PbI₃.     

A review on two-dimensional (2D) and 2D-3D multidimensional perovskite solar cells: Perovskites structures,stability, and photovoltaic performances

Perovskite solar cells (PSCs) fabricated with two-dimensional (2D) halide and 2D-3D mixed-halide materials are remarkable for their optoelectronic properties. The 2D perovskite structures are extremely stable but show limited charge transport and large bandgap for solar cell applications. To overcome these challenges, multidimensional 2D-3D perovskite materials are used to maintain simultaneously, a long-term stability, and high performance. In this review, we discuss the recent progress and the advantages of 2D and 2D-3D perovskite materials as absorber for solar cell applications. First, we discuss the structure and the unique properties of 2D and multidimensional 2D-3D perovskites materials. Second, the stability of 2D and 2D-3D mixed perovskites and the perspects of PSCs are hashed out.     

A two‐dimensional organic–inorganic hybrid perovskite‐type semiconductor: poly[(2‐azaniumylethyl)trimethylphosphanium [tetra‐μ‐bromido‐plumbate(II)]]

Recently, with the prevalence of `perovskite fever', organic–inorganic hybrid perovskites (OHPs) have attracted intense attention due to their remarkable structural variability and highly tunable properties. In particular, the optical and electrical properties of organic–inorganic hybrid lead halides are typical of the OHP family. Besides, although three‐dimensional hybrid perovskites, such as [CH₃NH₃]PbX₃ (X = Cl, Br or I), have been reported, the development of new organic–inorganic hybrid semiconductors is still an area in urgent need of exploration. Here, an organic–inorganic hybrid lead halide perovskite is reported, namely poly[(2‐azaniumylethyl)trimethylphosphanium [tetra‐μ‐bromido‐plumbate(II)]], {(C₅H₁₆NP)[PbBr₄]}_n, in which an organic cation is embedded in inorganic two‐dimensional (2D) mesh layers to produce a sandwich structure. This unique sandwich 2D hybrid perovskite material shows an indirect band gap of ～2.700 eV. The properties of this compound as a semiconductor are demonstrated by a series of optical characterizations and indicate potential applications for optical devices.     

钙钛矿太阳能电池电子传输层的制备及应用

目前,有机-无机杂化钙钛矿太阳能电池(PSC)的器件效率已经超过25%。电子传输层作为PSC中的重要组成部分在提取和传输光生电子,阻挡空穴,修饰界面,调节界面能级和减少电荷复合等方面起着关键作用。无机n型材料,例如TiO₂、ZnO、SnO₂和其他金属氧化物材料具有成本低和稳定性好的特点,经常在传统PSC中被用作电子传输层(ETL)。有机n型材料,例如富勒烯及其衍生物、萘二酰亚胺聚合物和小分子,具有良好的成膜性能及强的电子传输性能,经常在反式PSC中被用作ETL。本综述详细介绍了PSC中电子传输层的作用机理和制备方法;重点总结了金属氧化物材料、有机分子材料、复合材料和多层分子材料电子传输层和其改性手段的最新研究进展;最后,展望了电子传输层材料朝着高性能PSC的实际应用和发展前景。