0D and 2D: The Cases of Phenylethylammonium Tin Bromide Hybrids

Journal Article · Tue May 05 00:00:00 EDT 2020 · Chemistry of Materials

DOI:https://doi.org/10.1021/acs.chemmater.0c01254· OSTI ID:1649412

Xu, Liang-Jin ^[1]; Lin, Haoran ^[1]; Lee, Sujin ^[1]; Zhou, Chenkun  ^[1]; Worku, Michael ^[1]; Chaaban, Maya ^[1]; He, Qingquan ^[1]; Plaviak, Anna ^[1]; Lin, Xinsong ^[1]; Chen, Banghao ^[1]; Du, Mao-Hua  ^[2]; Ma, Biwu  ^[1]

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1. Florida State Univ., Tallahassee, FL (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Tin halide perovskites and perovskite-related materials have emerged as promising lead-free hybrid materials for various optoelectronic applications. While remarkable progress has been achieved in the development of organic tin halide hybrids with diverse structures and controlled dimensionalities at the molecular level, some controversial results that have been reported recently need to be addressed. For instance, different photophysical properties have been reported for two-dimensional (2D) (PEA)₂SnBr₄ (PEA = phenylethylammonium) by several groups with distinct emission peaks at around 468 and 550 nm. Here we report our efforts in the synthesis of phenylethylammonium tin bromide hybrids with zero-dimensional (0D) and 2D structures, and characterizations of their structural and photophysical properties. 0D [(PEA)₄SnBr₆][(PEA)Br]₂[CCl₂H₂]₂ was found to exhibit strong yellow emission peak at 566 nm with a photoluminescence quantum efficiency (PLQE) of ~90%, while 2D (PEA)₂SnBr₄ had weak emission peak at 470 nm with a PLQE of <0.1%. Interestingly, 0D [(PEA)₄SnBr₆][(PEA)Br]₂[CCl₂H₂]₂ can be converted into 2D (PEA)₂SnBr₄ upon drying, which would return to 0D [(PEA)₄SnBr₆][(PEA)Br]₂[CCl₂H₂]₂ upon addition of dichloromethane. Powder X-ray diffraction results confirmed the reversible transformation between 0D and 2D structures. Density functional theory calculations showed that excitons in 0D [(PEA)₄SnBr₆][(PEA)Br]₂[CCl₂H₂]₂ are highly localized, resulting in a strongly Stokes shifted broadband emission, while delocalized electronic states in 2D (PEA)₂SnBr₄ result in weaker exciton binding, a higher exciton mobility, and a higher nonradiative decay.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1649412
• Journal Information: Chemistry of Materials, Vol. 32, Issue 11; ISSN 0897-4756
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY