Synthesis, characterization and phase transitions in the inorganic–organic layered perovskite-type hybrids [(C _n H_2n + 1NH₃)₂PbI₄], n = 4, 5 and 6

Abstract

Three inorganic-organic layered perovskite-type hybrids of the general formula [(C(n)H(2n+1)NH(3))(2)PbI(4)], n = 4, 5 and 6, display a number of reversible first-order phase transitions in the temperature range from 256 to 393 K. [(C(4)H(9)NH(3))(2)PbI(4)] has a single phase transition, [(C(5)H(11)NH(3))(2)PbI(4)] has two phase transitions and [(C(6)H(13)NH(3))(2)PbI(4)] has three phase transitions. In all three cases, the lowest-temperature phase transition is thermochromic and the crystals change colour from yellow in their lowest-temperature phase to orange in their higher-temperature phase for [(C(4)H(9)NH(3))(2)PbI(4)] and [(C(6)H(13)NH(3))(2)PbI(4)], and from orange to red for [(C(5)H(11)NH(3))(2)PbI(4)]. The structural details associated with this phase transition have been investigated via single-crystal X-ray diffraction, SC-XRD, for all three compounds.

Structural, optical properties and characterization of (C2H5NH3)2CdCl4, (C2H5NH3)2CuCl4 and (C2H5NH3)2Cd0.5Cu0.5Cl4 compounds

“…(αhν ) ଶ = A(hν − Eg) (8) Where A is a constant, hν is the photon energy and E g is the optical band gap energy.…”

“…The electronic structure of [(C n H 2n+1 )NH 3 ] 2 MX 4 is regarded as a self-organized multiple-quantum-well structure consisting of inorganic wells and organic barriers. For compounds with short chain length n≤4 and M=Mn 2+ , Fe 2+ , Cu 2+ , Cd 2+ or Pb 2+ , the metal ion extends in layers of associated [MX 6 ] octahedra [8][9][10][11] and for M=Co 2+ and Zn 2+ unassociated tetrahedra [MCl 4 ] arrangement is observed [12][13]. For these hybrid compounds, the physical properties depend on the characteristics of the organic cation and the inorganic anion, which allows the properties of the material to be tailored [14][15].…”

Two-Dimensional Halide Perovskites for Emerging New- Generation Photodetectors

“…Recently, Cortecchia et al found that a significant deformation of the Pb − X bond length and the X − Pb − X bond angle can result in broadened PL spectra for the two perovskites, (NBT) 2 PbI 4 [71] and (EDBE)PbI 4 [72] (NBT = n-butylammonium and EDBE = 2,2-(ethylenedioxy)bis(ethylammonium)) [73]. …”

Heterometal silver/copper(I) modulated thermochromism of two isostructural iodoplumbates

“…Although Pb is a neighboring element of Bi with similar cation size and octahedral coordination character [13,19], their different oxidation states endow them with specific structural buildings and functional features. Typically, thermochromism as an interesting phenomenon has attracted much attention in the field of iodobismuthate or iodoplumbate hybrids [8,12,[20][21][22][23][24][25][26][27]. Differing from the thermochromic iodobismuthates, only a handful of thermochromic layered perovskite-type iodoplumbates [22][23][24][25][26][27] and two thermochromic heterometallic iodoplumbates ([Co(phen) 3 ] 2 [Pb 3 Cu 6 I 16 ] Á C 2 H 5 OH [12] and [Pb 3 I 10 Cu 4 (phen) 2 ] n ) [8] have been reported, which is likely due to their larger energy gap and limited response of their structures to the temperature.…”