Efficient orange self-trapped exciton emission from Sb3+-doped (DMA)4InCl7 single crystals

Developing efficient lead-free organic-inorganic hybrid metal halides (OIHMHs) remains a significant challenge due to inherent structural limitations. This study reports the synthesis of Sb 3+ -doped zero-dimensional (DMA) 4 InCl 7 single crystals (>0.5 cm) via a solvent-antisolvent method, notably without the use of DMACl precursors. Sb 3+ doping induces local lattice distortion, reducing the bandgap from 3.59 eV to 3.28 eV and resulting in intense orange self-trapped exciton (STE) emission at 560 nm, with a high photoluminescence quantum yield (PLQY) of 54.76 %. Density functional theory (DFT) calculations reveal that Sb 3+ -induced impurity states enhance electron-phonon decoupling and facilitate radiative recombination. A concept-validation device fabricated by directly coupling the crystal to a UV-LED chip produces stable yellow emission (CIE: 0.38, 0.51), highlighting its potential for practical optoelectronic applications.