Modifying CH₃NH₃PbBr₃ nanocrystals with arylamines

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• 作者：Ruimin Zhu^a ; Heyuan Liu^b ; Li Shen^b ; Dejun Sun^a ; ; Xiyou Li^a ; ^b ; ^{xiyouli@sdu.edu.cn}
• 关键词：CH3NH3PbBr3 perovskite nanocrystals ; Arylamine ; Surface functionalization ; Steric hindrance ; Alkalinity
• 刊名：Journal of Physics and Chemistry of Solids
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：103
• 期：Complete
• 页码：164-169
• 全文大小：673 K
• 卷排序：103

文摘

Chemically decorating CH3NH3PbBr3 with a group of para-substituted arylamine (R-An) was investigated, where R ranges from electron-withdrawing trifluoromethoxy(-CF3O), to hydrogen or electron-donating ethoxy (-EtO). Different ratios of R-An ammonium bromide and methylammonium bromide (MA) (R-An/MA=3/7, 4/6, 5/5, 6/4 and 7/3) were tested. XRD patterns revealed that the perovskite nanocomposite were cubic with good crystallinity. TEM and photoluminescence suggested that the perovskite nanocrystals were composed of 2D layered and 3D bulk structures. 1H NMR and TGA experiments revealed that the non-substituted aniline can readily adsorb to the surface of perovskite at any ratios between R-An and MA. But an EtOAn/MA ratio ≥1 is needed to anchor the EOAn molecules on the surface of perovskite. For the arylamine with the electron-withdrawing -CF3O group, it cannot adsorb to the surface of the perovskite at any concentrations. This result reveals that both steric hindrance and alkalinity can affect the anchoring of arylamine on the surface of CH3NH3PbBr3 perovskite. I-V curves of the perovskite nanocrystal films prepared by spin coating suggest that proper surface modification can increase the conductivity significantly.