Light Emitting Metal-Organic Halide 1D and 2D Structures: Near-unity Quantum Efficiency, Low-loss Optical Waveguide and Highly Polarized Emission.

Organic-inorganic metal-halide materials (OIMMs) with zero-dimensional (0D) structure have recently attracted increasing attention owing to their excellent optical properties and widely photo-functional applications. However, successful examples of 0D structural OIMMs with well-defined optical  performance at micro-/nanometer size are still quite limited. Here, we design and synthesise  a one-dimensional (1D) (DTA) 2 SbCl 5 ·DTAC (DTAC=Dodecyl trimethyl ammonium chloride) single crystal micro-rod and 2D micro-plates with 0D structure, in which individual (SbCl 5 ) 2- quadrangular units are completely isolated and surrounded by the organic cation DTA + . Experimental results indicate that the organic molecular unit with a long alkyl chain (C 12 ) and three methyl groups enables the formation of micro-rods and micro-plates. The single crystal micro- rods/plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence  quantum yield (PLQY) of around 90% and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self-trapping excitons as determined by the joint experiment-theory studies. Spatially resolved PL spectra confirm that the micro-rods exhibit an optical waveguide effect with low waveguide loss coefficient (0.0019 dB μm -1 ) during propagation, and linear polarized photoemission with polarization contrast (0.57). These features present a new direction towards the design of 0D OIMMs with various morphologies, which also further extend the applications of 0D OIMMs to potential optical communication micro-devices.