14846-47-0Relevant articles and documents
A new organic-inorganic bismuth halide crystal structure and quantum dot bearing long-chain alkylammonium cations
Wang, Jiandong,Li, Jia,Wang, Yong,Xiao, Wen-Jing,Yao, Xiang,Xu, Zi-Wen,Yao, Jianhua,Lin, Jian,Li, Wei-Shi
, p. 155 - 161 (2019)
It is report here a new family of organic-inorganic bismuth halides bearing a formula of A2BiX5, in which A is monovalent long-chain alkylammonium and X is halide. Two compounds, (BA)2BiBr5 (BA: C4H9NH3 +) and (OA)2BiBr5 (OA: C8H17NH3 +), have been synthesized and investigated by single crystal and powder X-ray diffractions, UV–vis absorption and fluorescence spectroscopies, and density functional theoretical calculations. An orthorhombic crystalline structure with a P212121 space group, which had not been reported for organobismuth halides before, was found existing in (OA)2BiBr5 single crystals. Besides bulk materials, the quantum dots (QDs) of (BA)2BiBr5 and (OA)2BiBr5 were prepared and demonstrated as blue emitters with photoluminescent quantum yields of 1.26% and 0.50%, respectively, after capping with oleic acid. Finally, mixed halides with various I/Br ratios were prepared and found to form certain solid solutions with homogeneous distributed I? and Br?. Upon tuning I/Br ratio, the absorption and emission bands of their QDs can be easily modulated.
CH3NH3PbBr3 Perovskite Nanocrystals as Efficient Light-Harvesting Antenna for Fluorescence Resonance Energy Transfer
Muthu, Chinnadurai,Vijayan, Anuja,Nair, Vijayakumar C.
, p. 988 - 995 (2017)
Hybrid perovskites have created enormous research interest as a low-cost material for high-performance photovoltaic devices, light-emitting diodes, photodetectors, memory devices and sensors. Perovskite materials in nanocrystal form that display intense luminescence due to the quantum confinement effect were found to be particularly suitable for most of these applications. However, the potential use of perovskite nanocrystals as a light-harvesting antenna for possible applications in artificial photosynthesis systems is not yet explored. In the present work, we study the light-harvesting antenna properties of luminescent methylammonium lead bromide (CH3NH3PbBr3)-based perovskite nanocrystals using fluorescent dyes (rhodamine B, rhodamine 101, and nile red) as energy acceptors. Our studies revealed that CH3NH3PbBr3 nanocrystals are an excellent light-harvesting antenna, and efficient fluorescence resonance energy transfer occurs from the nanocrystals to fluorescent dyes. Further, the energy transfer efficiency is found to be highly dependent on the number of anchoring groups and binding ability of the dyes to the surface of the nanocrystals. These observations may have significant implications for perovskite-based light-harvesting devices and their possible use in artificial photosynthesis systems.
Controlled synthesis of brightly fluorescent CH3NH3PbBr3 perovskite nanocrystals employing Pb(C17H33COO)2 as the sole lead source
Fu, Xiaoming,Peng, Zhiwei,Zhang, Chi,Xia, Yong,Zhang, Jianbing,Luo, Wei,Guo, L. Jay,Li, Honglang,Wang, Yuhuang,Zhang, Daoli
, p. 1132 - 1139 (2018)
Organometal halide perovskite nanocrystals hold vast potential for application in photovoltaics, light emitting diodes, low-threshold lasers, and photodetectors due to their size-tunable bandgap energies and photoluminescence as well as excellent electron and hole mobilities. However, the synthesis of such nanocrystals typically suffers from poor structural stability in solution and the coexistence of lamellate nanocrystals (nanoplatelets) and spherical nanocrystals (nanoparticles). Here we show that the pure nanoparticle morphology of CH3NH3PbBr3 nanocrystals can be realized by employing lead oleate (Pb(C17H33COO)2) as the sole lead source and controlled using short- and long-chain mixed alkyl ammonium. These nanocrystals are monodispersed (2.2 ± 0.4 nm in diameter), highly fluorescent (with a quantum yield approaching 85%), and highly stable in the solution (for more than 30 days). Comparative studies reveal that the shape of CH3NH3PbBr3 nanocrystals is strongly dependent on the lead source, PbBr2 and Pb(C17H33COO)2, and evolves as a function of the ratio of short- and long-chain alkyl ammoniums in the precursors. At an optimal short to long-chain alkyl ammonium ratio of 4:6, the growth of CH3NH3PbBr3 nanoplatelets can be selectively suppressed with Pb(C17H33COO)2 as the sole lead source, enhancing the overall photoluminescence quantum yield of the produced CH3NH3PbBr3 nanocrystals. This work reveals important new insights for controlled synthesis of perovskite nanocrystals with pure crystal shape and significantly improved photoluminescence properties and stability.
Thousand-fold Conductivity Increase in 2D Perovskites by Polydiacetylene Incorporation and Doping
Ortiz-Cervantes, Carmen,Román-Román, Priscila I.,Vazquez-Chavez, Josué,Hernández-Rodríguez, Marcos,Solis-Ibarra, Diego
, p. 13882 - 13886 (2018)
Two-dimensional (2D) organic–inorganic perovskites have rapidly become an attractive alternative to traditional three-dimensional (3D) perovskite solar-cell absorbers owing to their improved stability and processability. Despite their advantages, the insulating nature of the organic cations and diminished light absorption limit their overall performance. Herein, it is demonstrated that the incorporation of conjugated diynes in hybrid 2D perovskites, and subsequent thermal treatment results in the formation of 2D perovskites that incorporate polydiacetylenes in their structure. Furthermore, it is shown that oxygen or iodine doping results in the formation of stable radicals within the material alongside a drastic shift of the band gap from 3.0 to 1.4 eV and in-plane conductivity improvements of up to three orders of magnitude, which lead to record conductivities for 2D halide perovskites (n=1).
