Solution Route to Single-Crystalline Ethylammonium Lead Halide Microstructures

Organic-inorganic lead halide single crystals have shown great promise for their unique properties and potential applications in next-generation optoelectronic devices. In this paper, solution syntheses of single-crystalline ethylammonium lead halide microstructures were reported. The Br-containing product grown at a low C2H5NH3Br concentration exhibits an interesting crossed-plate morphology and possesses a chemical formula of (C2H5NH3)(4)Pb3Br10, yet the product synthesized at a high C2H5NH3Br concentration shows a block-like morphology and adopts a chemical formula of (C2H5NH3)(2)PbBr4. The I-containing product shows a rod or polyhedron shape and has the chemical formula of (C2H5NH3)PbI3. Time dependent experiments were carried out to reveal their growth mechanisms. The optical absorption spectra show that the (C2H5NH3)(4)Pb3Br10 and (C2H5NH3)(2)PbBr4 possess exciton absorptions at 2.95 eV and 3.19 eV, respectively. And the C2H5NH3PbI3 shows a much sharper exciton absorption at 2.61 eV.