Nanocrystalline/microcrystalline materials based on lead-halide units
Nanocrystalline/microcrystalline materials based on lead-halide units
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DOI：
10.1039/c2jm15783g
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发表时间：
2012-01-01
影响因子：
--
通讯作者：
Vassilakopoulou, Anastasia
中科院分区：
文献类型：
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作者：
Papavassiliou, George C.;Pagona, Georgia;Vassilakopoulou, Anastasia
本文报道了以几种宏观形式的铅(BrxCl1-x)(3)、铅(BrxI1-x)(3)和铅(ClxI1-x)(3)(x=0-1)为基元的颗粒状(纳米晶/微晶)材料的制备、光致发光光谱和相关性质。甲苯悬浮液或含有聚甲基丙烯酸甲酯(PMMA)的甲苯悬浮液是从相应的n层材料(或其前驱体)中主要通过类似滴定的方法获得的。这是将含Pbn-n(BrxCl1-x)(3n+1)、Pbn(BrxI1-x)(3n+1)和Pbn(ClxI1-x)(3n+1)(n>；2)单元的相应化合物的溶液注入到整齐的甲苯或甲苯-PMMA中，并平行观察光致发光光谱。利用这种方法，可以控制卤化铅材料的质量，并可以在较宽的光谱范围内(即从大约400 nm到大约700 nm)调节低频发光带的位置。从甲苯悬浮液中，通过离心法和沉降法获得了沉淀物(粉末)形式的相应材料。以甲苯-PMMA为悬浮液，采用滴注法、深涂法和/或旋涂法制备了以PMMA为基质的复合薄膜材料。因此，我们得到了蓝、绿、黄、红四种窄带(20-35 nm)(悬浮体、粉末和薄膜)的发光材料，并进一步研究了它们的发光光谱和光学吸收光谱。光致发光强度的变化与CsBR基质中的CsPbBr3粒子的情况相同。此外，还发现与金属硫化物量子点的光谱有一些相似之处。它们被认为是几种光学和光电子学应用的候选材料。
The preparation, photoluminescence (PL) spectra and related properties of particulate (nanocrystalline/microcrystalline) materials based on Pb(BrxCl1-x)(3), Pb(BrxI1-x)(3), and Pb(ClxI1-x)(3) (x = 0-1) units, in several macroscopic forms, are reported. The materials in the form of suspensions in toluene or in toluene containing polymethyl methacrylate (PMMA) were obtained from the corresponding n-layer materials (or their precursors), mainly, by a titration-like method. This is the injection of solutions of the corresponding compounds with the Pb-n(BrxCl1-x)(3n+1), Pb-n(BrxI1-x)(3n+1), and Pb-n(ClxI1-x)(3n+1) (n > 2) units, respectively, into neat toluene or toluene-PMMA, with parallel observation of the PL-spectra. With this method, the mass of the lead-halide materials is controlled and the position of the low frequency PL band could be tuned in a wide spectral range, i.e., from ca. 400 to ca. 700 nm. From the suspensions in toluene the corresponding materials in the form of precipitates (powders) were obtained by centrifugation and decantation. From suspensions in toluene-PMMA, the corresponding materials in the form of composite thin films (of PMMA-matrix) were obtained by drop-casting, deep-coating and/or spin-coating techniques. So, blue, green, yellow and red narrow PL-band (of 20-35 nm) emitters (in forms of suspensions, powders and films) were obtained and their PL and optical absorption spectra were investigated further. The PL-intensity varies as in the case of CsPbBr3 particles in a CsBr matrix. Also, some similarities with the spectra of metal chalcogenide quantum dots were found. They were suggested as candidate materials for several optical and optoelectronic applications.