Zero-Dimensional Hybrid Antimony Chloride with Near-Unity Broad-Band Orange-Red Emission toward Solid-State Lighting

High External Quantum Efficiency and Dual-Band Emission of (C7H18N)3Sb2Cl9 for Sensitivity Temperature Sensing

Organic-inorganic hybrid halides have gained attention for their ease of processing and remarkable optoelectronic properties. However, the relationship between the structure and optical properties requires further exploration. In this study, the butyltrimethylammonium cation (C7H18N+) was chosen, and seven compounds were synthesized: (C7H18N)3Sb2X9 (X = Cl, Br), (C7H18N)3Bi2X9 (X = Cl, Br, I), and (C7H18N)(C2H8N)MBr5 (M = Sb, Bi). Crystals with a single organic cation exhibit a zero-dimensional structure, while the introduction of dimethylamine ions increases the crystal dimensionality from zero-dimensional (C7H18N)3Sb2Br9 to one-dimensional (C7H18N)(C2H8N)SbBr5. Under 372 nm excitation, (C7H18N)3Sb2Cl9 showed broad orange-red single-band emission with a high photoluminescence quantum yield of 88.4% and an external quantum efficiency of up to 56.9%. A white light-emitting diode based on (C7H18N)3Sb2Cl9 achieved a high color rendering index of 96.3. Moreover, dual-band emission was observed in (C7H18N)3Sb2Cl9 under 308 nm excitation, which exhibits an absolute temperature sensitivity of 1.96 × 10-3 K-1 (320 K), and a flexible film was prepared by incorporating polydimethylsiloxane. This shows the promise of hybrid metal halides as photoluminescent materials and their possibilities for temperature sensing.

Excited State Regulated Emission in Hybrid Indium Halides via Crystal Structure Switch

Organic-inorganic metal halides have become one of the most promising materials in the next generation of optoelectronic applications due to their high charge carrier mobility and tunable band gaps. In this study, Sb:PA6InCl9 and Sb:PA4NaInCl8 single crystals were prepared through evaporation crystallization, respectively. Due to the different degrees of lattice distortions, the highly efficient yellow emission in Sb:PA6InCl9 at 610 nm and the green emission in Sb:PA4NaInCl8 at 545 nm were achieved by regulation of the excited state, respectively. By introducing additional sodium ions in the post-treatment, we found that the zero-dimensional Sb:PA6InCl9 could rapidly convert into a two-dimensional layered structure of Sb:PA4NaInCl8, thus resulting in a novel green/yellow emission switch. This work guides the structural and performance control of organic-inorganic hybrid In-based metal halides and offers broad prospects for luminescent switching in anticounterfeiting applications.