Light‐Emitting Metal–Organic Halide 1D and 2D Structures: Near‐Unity Quantum Efficiency, Low‐Loss Optical Waveguide and Highly Polarized Emission

Abstract Organic–inorganic metal‐halide materials (OIMMs) with zero‐dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well‐defined optical performance at the micro‐/nanometer scale are limited. We prepared one‐dimensional (1D) (DTA) 2 SbCl 5 ⋅DTAC (DTAC=dodecyl trimethyl ammonium chloride) single‐crystal microrods and 2D microplates with a 0D structure in which individual (SbCl 5 ) 2− quadrangular units are completely isolated and surrounded by the organic cation DTA + . The organic molecular unit with a long alkyl chain (C 12 ) and three methyl groups enables microrod and ‐plate formation. The single‐crystal microrods/‐plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self‐trapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB μm −1 ) during propagation, and linear polarized photoemission with a polarization contrast (0.57).