High-Efficiency Intrinsic Yellow-Orange Emission in Hybrid Indium Bromide with Double Octahedral Configuration

Abstract

In-based organic−inorganic metal halides (OIMHs) have received growing interest in recent years as promising luminescent materials. However, the high efficiencies of 0D In-based OIMHs are all dependent on Sb doping in the existing literature. Here, we report a novel 0D In-based OIMH (C 10 H 22 N 2 ) 2 In 2 Br 10 , which exhibits intrinsic broadband emission (610 nm), and the photoluminescence quantum yield (PLQY) can reach 70% without Sb doping. (C 10 H 22 N 2 ) 2 In 2 Br 10 shows a typical 0D structure with three different In−Br polyhedra (two octahedra and one tetrahedron) separated by large organic cations. Based on the optical property measurements and theoretical calculations, we demonstrate that (C 10 H 22 N 2 ) 2 In 2 Br 10 is an indirect semiconductor with a band gap of 3.74 eV, and the In−Br inorganic moiety is primarily responsible for the intense emission of (C 10 H 22 N 2 ) 2 In 2 Br 10 . Interestingly, the unique double octahedral configuration in (C 10 H 22 N 2 ) 2 In 2 Br 10 may enhance the structural distortion and stimulate the self-trapped excitons (STEs), leading to the related high PLQY. Our work provides a novel 0D In-based OIMH with high-efficiency intrinsic emission, which is helpful for understanding the structure−PL relationships of hybrid halides.

Lead-free hybrid indium perovskites with near-unity PLQY and white light emission using an Sb3+doping strategy

“…The distance of H⋯Cl ranges from 2.38(3) Å to 2.633(8) Å, D⋯A distances range from 3.109(9) Å to 3.279(8) Å and D-H⋯A angles range from 129.45 (15) to 172(6)°. Based on previous studies, 17 we found that the emission efficiency of 0D metal halides is affected by the concentration of luminescent active centers, that is, the distance between adjacent [InCl 6 ] 3− anions. From Fig.…”

“…[12][13][14] Recently, Yue et al 15 ) + ] indium-based hybrid halides, which exhibited strong broadband orange luminescence with a PLQY of about 35%. 16 Subsequently, Yuan et al 17 reported 0D In-based OIMH (C 10 H 22 N 2 ) 2 In 2 Br 10 with high-efficiency intrinsic emission and a PLQY of up to 70%. Although relatively high PLQY pristine organic-inorganic indium halides have been reported, their PLQY is still not satisfactory.…”

Supramolecular-Interactions-Modulated Photoluminescence in Indium Bromide-Based Isomers

“…Over the past few years, researchers have found that zero-dimensional ionic indium-based IOMHs are stable and low-toxicity materials with excellent luminescence properties. − Notably, while possessing organic cations, the anionic indium halide moieties in these ionic IOMHs are mostly pure inorganic such as octahedral (InX 6 ) 3– , conical (InX 5 ) 2– , tetrahedral (InX 4 ) − , , and dimeric (In 2 X 10 ) 4– (X = Cl, Br, I). , As is known, the coordination of organic ligands such as conjugated 2,2′-bipyridal and 1,10-phenanthroline (Phen) into inorganic halometalate units can lead to colorful PL arising from various mechanisms such as halogen-to-ligand charge transfer, ligand-to-metal charge transfer, and inorganic-to-organic charge transfer (IOCT). − Thus, it is anticipated that different combinations of organic ligands and cations can make the PL properties of indium-based IOMHs highly adjustable due to the variety of PL mechanisms and supramolecular interactions inside.…”

“…Over the past few years, researchers have found that zerodimensional ionic indium-based IOMHs are stable and lowtoxicity materials with excellent luminescence properties. 17−22 Notably, while possessing organic cations, the anionic indium halide moieties in these ionic IOMHs are mostly pure inorganic such as octahedral (InX 6 ) 3− , 20 conical (InX 5 ) 2− , 18 tetrahedral (InX 4 ) − , 19,23 and dimeric (In 2 X 10 ) 4− (X = Cl, Br, I). 19,21 As is known, the coordination of organic ligands such as conjugated 2,2′-bipyridal and 1,10-phenanthroline (Phen) into inorganic halometalate units can lead to colorful PL arising from various mechanisms such as halogen-to-ligand charge transfer, ligand-to-metal charge transfer, and inorganic-toorganic charge transfer (IOCT).…”

Halogen Effect on the Photoluminescence of 1D Hybrid Lead Halide Perovskites with a Bipyridinium Cation

“…33 The normalized PL spectra in Figure 5c demonstrate that the relative intensity of the HE emission band at 430 nm gradually decreases, while that of the LE band at 550 nm gradually increases as the temperature increases from 118 to 348 K. This can be explained by the fact that, as the temperature increases, more excitons are activated and transition into a more stable STE state with enhanced relative intensity. Furthermore, because of the enhanced electron− phonon coupling at higher temperatures, the fwhm of the STE emission at 550 nm broadens distinctly, 34,35 while that of the FE emission at 430 only shows minor variations (Figure 5e). The emission peaks of PCl exhibit a blue-shift phenomenon as the temperature decreases (Figure 5c), which may be attributed to the enhanced rigid environment around the inorganic moieties at low temperatures, resulting in a smaller Stokes shift.…”