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

Abstract

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.

Synthesis, structure, and photoluminesence of the chloridoaluminates [BMIm][Sn(AlCl4)3], [BMPyr][Sn(AlCl4)3], and [BMIm][Pb(AlCl4)3]

“…24,25 Such semiconductor-based luminescence leads to high quantum yields of nanoparticles. For instance, [(PEA) 4 SnBr 6 ][(PEA)Br]•(CCl 2 H 2 ) 2 exhibits excellent efficiency as a zero-dimensional quantum dot (90%), 26 whereas two-dimensional infinite layers of the compound have only a marginal quantum yield (0.1%) (Table 3).…”

Metal Halide Regulated Photophysical Tuning of Zero‐Dimensional Organic Metal Halide Hybrids: From Efficient Phosphorescence to Ultralong Afterglow

“…These hybrid materials provide an excellent platform for metal halide species to exhibit their intrinsic properties, when wide‐band‐gap organic cations are used to form perfect host–guest systems. During the last couple of years, a large number of 0D organic metal halide hybrids have been developed to exhibit tunable emissions covering the whole visible spectrum, from blue to green, yellow, orange, and red, by controlling the metal halide emitting centers [2d, e, 3] . The topology of metal halides can also be well controlled, from octahedron to pyramidal, see‐saw structure, linear and triangular trimer clusters, and so on [2d,e, 3, 4] .…”

“…During the last couple of years, a large number of 0D organic metal halide hybrids have been developed to exhibit tunable emissions covering the whole visible spectrum, from blue to green, yellow, orange, and red, by controlling the metal halide emitting centers [2d, e, 3] . The topology of metal halides can also be well controlled, from octahedron to pyramidal, see‐saw structure, linear and triangular trimer clusters, and so on [2d,e, 3, 4] . Not only single component systems, but also multicomponent systems have been developed, allowing single phase materials to exhibit simultaneous emissions of different colors from distinct metal halide species [5] .…”

Scintillation in (C6H5CH2NH3)2SnBr4: green-emitting lead-free perovskite halide materials

“…The orthorhombic unit cell of (CH 3 (CH 2 ) 7 NH 3 ) 2 SnBr 4 retrieved from Cao et al 15 and the triclinic unit cell of (C 6 H 5 (CH 2 ) 2 -NH 3 ) 2 SnBr 4 retrieved from Xu et al 21 were used for the (CH 3 (-CH 2 ) 7 NH 3 ) 2 SnBr 4 and (C 6 H 5 CH 2 NH 3 ) 2 SnBr 4 calculations, respectively. The Kohn-Sham formulation 22,23 as implemented in the Vienna Ab initio Simulation Package (VASP) 24,25 was used for the calculations.…”