Sb³⁺-Doped Indium-Based Metal Halide (Gua)₃InCl₆ with Efficient Yellow Emission

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photophysics

Background:

• Low-dimensional organic-inorganic hybrid metal halides (OIHMHs) exhibit notable photophysical properties due to their quantum structure and tunable energy levels.
• Energy transfer between inorganic and organic components in OIHMHs is a key factor driving research interest.
• Self-trapped excitons (STEs) play a crucial role in the luminescence mechanisms of halide-based materials.

Purpose of the Study:

• To synthesize a novel zero-dimensional (0D) OIHMH, Sb³⁺:(Gua)₃InCl₆, by doping (Gua)₃InCl₆ with Sb³⁺.
• To investigate the significant enhancement in photoluminescence (PL) and photoluminescence quantum yield (PLQY) of the doped material.
• To elucidate the underlying mechanism of enhanced luminescence through combined experimental and theoretical approaches.

Main Methods:

• Synthesis of Sb³⁺-doped (Gua)₃InCl₆ (0D OIHMH).
• Photoluminescence (PL) spectroscopy, including temperature-dependent measurements.
• Ultrafast femtosecond transient absorption spectroscopy.
• Density functional theory (DFT) calculations.

Main Results:

• The Sb³⁺-doped OIHMH showed a dramatic increase in PL emission at 580 nm, with PLQY boosted from 17.86% to 95.72%.
• Excitation at 340 nm led to this enhanced emission, indicating efficient energy absorption and conversion.
• Combined spectroscopic and DFT analyses revealed simultaneous light emission from both Sb and In sites via self-trapped exciton (STE) recombination.
• The material demonstrated potential for application in photoelectric devices.

Conclusions:

• The Sb³⁺ doping strategy is highly effective in enhancing the luminescence of 0D OIHMHs.
• Simultaneous STE recombination at both dopant (Sb) and host (In) sites contributes to the strong emission.
• This study provides fundamental insights into STE dynamics in In-based halides and guides the design of advanced luminescent materials.