화학공학소재연구정보센터
학회 한국재료학회
학술대회 2019년 봄 (05/15 ~ 05/17, 평창 알펜시아 리조트)
권호 25권 1호
발표분야 G. 나노/박막 재료 분과
제목 Low-dimensional formamidinium lead bromide perovskite architectures via controllable solvent intercalation
초록 Organic-inorganic halide perovskites have been attracting attention as materials for light-emitting diodes (LEDs) due to unique emission properties, which include high color purity with a very narrow emission and tuning the emission wavelength easily through the adjustment of the halide components, covering the entire range of visible light. However, one roadblock to LED application is the low exciton binding energies, which results in low luminous efficiencies. One of the proposed strategies to enlarge the exciton binding energy is reduction of the dimensionality of the perovskite crystal structure. Here, we report highly luminescent thin films of formamidinium (FA) lead bromide perovskite (photoluminescence quantum yield, PLQY = 35.7%) via the formation of low dimensional architectures. A mixture of 3D FAPbBr3 and a new type of 2D perovskite FA2PbBr4 intercalated with dimethyl sulfoxide (DMSO) was formed by controlling the molar ratio of FABr/PbBr2 in the precursor solutions and annealing condition. A type I band alignment between the lower bandgap 3D FAPbBr3 and the higher bandgap 2D FA2PbBr4 was supported by density functional theory (DFT) calculations, which results in exciton confinement in the 3D phase and a substantial increase in PLQY. The composite films also exhibited excellent air and thermal stability. Details of analysis will be presented and discussed.
저자 신민규1, 김준연1, 정영광2, Tero-petri Ruoko3, Arri Priimagi3, Aron Walsh4, 신병하1
소속 1한국과학기술원, 2연세대, 3Tampere Univ. of Technology, 4Imperial College London
키워드 Perovskite; Low-dimensional perovskite; PLQY; FA2PbBr4-DMSO
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