Growth and optical, magnetic and transport properties of (C 4H9NH3)2MCl4 organic-inorganic hybrid films (M = Cu, Sn)

Films of (C4H9NH3)(2)MCl4 (M=Cu and Sn) organic-inorganic hybrid perovskites have been deposited in-situ by a single-source thermal ablation technique on glassy, crystalline and polymeric substrates. Independently of the substrate, the films were well crystallized, c-axis oriented and with a narrow rocking curve of the (0010) reflection (full width at half maximum < 1 degrees). The (0 0 l) reflections were consistent with those of the bulk orthorhombic phases and the "c" lattice parameters were 30.85 +/- 0.05 and 32.35 +/- 0.05 angstrom, for the Cu- and the Sn-compound, respectively. (C4H9NH3)(2)CuCl4 films had an optical absorption peak at 375 nm at room temperature. From the magnetic point of view they act as layered nanocomposites with a dominant ferromagnetic component localized in planes (2D magnetism). T-c was 7.3 +/- 0.1 K and a moderate easy-plane anisotropy was observed. The photoluminescence spectra of typical (C4H9NH3)(2)SnCl4 films at 12 K had a broad yellow band, which did not correspond to any significant peak in the absorption spectrum. The films were semiconducting down to 250 K or, in the case of the best samples, down to 200 K and became insulating at lower temperature. The resistivity of the best films was (5 +/- 1) 10(4) Omega cm at 300 K, and the energy gap was 1.11 eV.