Synthesis, crystal structure, and optical and thermal properties of (C4H9NH3)(2)MI(4) (M=Ge, Sn, Pb)
Synthesis, crystal structure, and optical and thermal properties of (C4H9NH3)(2)MI(4) (M=Ge, Sn, Pb)
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DOI：
10.1021/cm9505097
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发表时间：
1996-03-01
影响因子：
8.6
通讯作者：
Mitzi, DB
中科院分区：
文献类型：
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作者：
Mitzi, DB
在水合酸溶液中生长出了有机-无机层状钙钛矿（C4H9NH3）(2)MI(4) （M = Ge, Sn, Pb）的单晶。利用x射线衍射、热分析和光致发光光谱分析比较了晶体结构、金属原子孤对立体活度和物理性质与IVB族元素的关系。正交（C4H9NH3）(2)GeI4结构，在空间群Pcmn中细化，由单层厚的扭曲共享角的GeI6八面体钙钛矿片组成，由正丁基铵阳离子双层层分隔。（C4H9NH3）(2)SnI4和（C4H9NH3）(2)PbI4结构非常相似，但采用空间基Pbca，在二价IVB原子周围有更理想的八面体碘配位。在更普遍的锡（II）基家族中，（C4H9NH3）(2)(CH3NH3)(n-1)SnnI3n+1，标题半导体n = 1化合物与先前报道的半金属n = 3和金属n- >无穷成员之间的结构比较表明，钙钛矿片厚，Sn（II）单键立体化学活性，平均Sn- i键长度和该系列中的电导率之间存在相关性。（C4H9NH3）(2)GeI4熔体温度为222(2)℃，明显低于其整体分解温度，而（C4H9NH3）(2)SnI4 （T-m = 256(2)℃）和（C4H9NH3）(2)PbI4 （T-m = 285(4)℃）熔体/分解温度逐渐升高，熔体稳定性较差。标题化合物的室温光致发光在可见光范围内表现出明显的光谱峰，其中M = Ge、Sn和Pb化合物的峰值波长分别在690(5)、625(1)和525(1)nm之间变化。
Single crystals of the organic-inorganic layered perovskites (C4H9NH3)(2)MI(4) (M = Ge, Sn, Pb) have been grown from aqueous hydriodic acid solutions. X-ray diffraction, thermal analysis, and photoluminescence spectroscopy were used to compare crystal structure, metal atom lone-pair stereoactivity, and physical properties as a function of group IVB element. The orthorhombic (C4H9NH3)(2)GeI4 structure, refined in the space group Pcmn, consists of single-layer-thick perovskite sheets of distorted corner-sharing GeI6 octahedra separated by n-butylammonium cation bilayers. (C4H9NH3)(2)SnI4 and (C4H9NH3)(2)PbI4 are structurally very similar but adopt the space group Pbca, with a more ideal octahedral iodine coordination around the divalent group IVB atoms. Within the more general tin(II)-based family, (C4H9NH3)(2)(CH3NH3)(n-1)SnnI3n+1, a structural comparison between the title semiconducting n = 1 compound and the previously reported semimetallic n = 3 and metallic n --> infinity members demonstrates a correlation between perovskite sheet thickness, Sn(II) lone-pair stereochemical activity, average Sn-I bond length, and electrical conductivity within this series. While (C4H9NH3)(2)GeI4 melts at 222(2) degrees C, significantly below its bulk decomposition temperature, (C4H9NH3)(2)SnI4 (T-m = 256(2) degrees C) and (C4H9NH3)(2)PbI4 (T-m = 285(4) degrees C) melt/decompose at progressively higher temperatures and are less stable as a melt. Room-temperature photoluminescence from the title compounds exhibits a pronounced spectral peak in the visible range, with the peak wavelength varying between 690(5), 625(1), and 525(1) nm for the M = Ge, Sn, and Pb compounds, respectively.