Pivotal Role of A-Site Cations in Tailoring the Band-Edge States, Optical Properties, and Stability of 0D Hybrid Indium Chlorides

Abstract

Optoelectronic properties of organic−inorganic hybrid perovskites (ABX 3 ) or metal halides are governed primarily by the B and X-site ions due to their electronic contribution to the band edge. The A-site cations do not directly participate in the band edge; instead, they stabilize the crystal structures. Facilitating these A-site cations to contribute to the band edge can enable an additional degree of tunability to properties and expand the opportunities beyond B and X ions. Here, we rationally employ different A-site cations based on anilinium cations in Sb 3+ -doped zero-dimensional (0D) indium chlorides and illustrate their contribution to the band-edge states using experimental data and theoretical calculations. We demonstrate that a change in the A-site cation results in a change in the octahedral distance in the crystal structure. In addition to this, we show that the frontier orbitals of hybrid indium chlorides are delocalized across the inorganic and organic moieties, leading to significant changes in their optical properties. Consequently, Sb 3+ -doped hybrid indium chlorides show a broadband emission with a PLQY over 93% and remarkable spectral and structural stability in five different solvents, including water, for 21 days.

Temperature Dependent Hydrogen Bond Toward High Emission in an Emerging Indium‐Based Perovskite

“…This static disorder can also be described as the rotational disorder, which may be attributed to the two energetically favorable orientations of aniline rings in the crystal structure. [ 33 ] What's more, the lattice has sufficient space to accommodate these orientations; thus, leading to rotational disorder in the (PPDAH 2 ) 2 InCl 7 . Owing to the InCl bond distance in the range of 2.4680–2.5662 Å, the [InCl 6 ] 3− octahedra exhibit a weak Jahn–Teller distortion (measured at 300 K).…”

Highly efficient self-trapped exciton luminescence of Sb3+-doped (CH6N3)3BiCl6 for ethanol detection

“…Zero-dimensional (0D) organic-inorganic metal halide hybrids (MHHs) exhibit potential for application in fluorescence sensors, X-ray imaging, light-emitting diodes, and anti-counterfeiting, [1][2][3][4][5][6] owing to their strong quantum confinement effect and high photoluminescence quantum yield (PLQY). Compared to traditional CsPbX 3 (X = Cl À , Br À , I À ) metal halides, 0D MHHs not only exhibit good chemical stability but also offer a rich variety of structures and tunable PL.…”

Alkali metal salt-assisted crystal structure switch of hybrid indium halides with near-unity photoluminescence quantum yield

“…They used larger-sized organic molecules as the A-site cations to separate the three-dimensional closely packed inorganic polyhedra in all directions, forming isolated polyhedral structure units of zero-dimensional (0D) metal halides. [14][15][16][17][18][19][20][21] The organic cations isolate the inorganic polyhedra in three directions, thereby achieving a significant quantum confinement. Therefore, the quantum confinement effect in organic-inorganic hybrid 0D metal halides originates from the organic cations within the crystal, making their luminescence almost unaffected by the crystal size and exhibiting superior luminescence stability compared to APbX 3 perovskites.…”