Abstract:
The “organic-inorganic halide hybrids”, as the name suggests, are the class of
materials which incorporates both organic ammonium and inorganic metal halides in
single phase and exhibits different component-dependent interesting physical properties.
Originally known since the start of 20th century, the organic-inorganic halide hybrid
materials have emerged over last two decades with ample promises by featuring
pronounced structural diversity coupled with exciting range of remarkable dielectric,
ferroelectric, magnetic and optoelectronic properties.1–8 To mention, recent years have
seen unparalleled progress being achieved in photovoltaic properties of the perovskite
based materials CH3NH3MX3 (M = Pb, Sn; X = Br, I).7–11 With modern day materialsbased
research continuously focused on design and fabrication of multifunctional
materials, the hybrid halides with their broad range of exciting properties and application
can be claimed as truly multifunctional and are worthy to be focused on. Such diversity in
physical properties arises from the different components that these materials contain. To
describe, the organic ammonium cation with its own shape, size and dipole moment
influence the structural symmetry largely, often giving rise to ferroelectric or
piezoelectric states. The inorganic ions are seen to form various types of metal-halide
complexes and influence the optoelectronic and magnetic properties of the material.
Interestingly, as there are vast numbers of different ammonium ions, metal ions and
halides which can play role of possible components, permuting them can lead to
innumerable number of hybrids which can be studied. To mention, Cheetham et al. have
modified the traditional tolerance factor equation and predicted that over 400 hybrid
halides can have perovskite structures.
