Analysis of electrostatic stability and ordering in quaternary perovskite solid solutions

Abstract

There are three distinct classes of perovskite structured metal oxides, defined by the charge states of the cations: AIBVO3,AIIBIVO3, and AIIIBIIIO3. We investigated the stability of cubic quaternary solid solutions ABO3−A′B′O3 using a model of point-charge lattices. The mixing enthalpies were calculated and compared for the three possible types of combinations of the compounds, both for the random alloys and the ground-state-ordered configurations. The mixing enthalpy of the (I,V)O3-(III,III)O3 alloy is always larger than the other alloys. We found that, different from homovalent alloys, for these heterovalent alloys a lattice constant mismatch between the constituent compounds could contribute to stabilize the alloy. At low temperatures, the alloys present a tendency to spontaneous ordering, forming superlattices consisting of alternated layers of ABO3 and A′B′O3 along the [110] direction

Advances in modelling and simulation of halide perovskites for solar cell applications

“…where E k (x) is the DFT total energy of the alloy with the mixing content x and the configuration number k, and g k is the degeneracy representing the number of configurations with the same energy E k . At room temperature, the internal energy of mixing can be well fitted into the subregular solution expression [76,157],…”

Hydrogen Bonding versus Entropy: Revealing the Underlying Thermodynamics of the Hybrid Organic–Inorganic Perovskite [CH3NH3]PbBr3

“…Entropy plays a critical role in determining the structural and dynamic properties of materials . In solid-state inorganic systems, the role of configurational disorder has long been recognized in the context of alloys and solid solutions. − In biological systems and solutions, the contribution of vibrational entropy has been shown to be of the utmost importance in driving phase equilibria. , Glass forming behavior is dependent on the combination of vibrational and configurational entropy. − In the context of hybrid organic–inorganic perovskites (HOIPs), we have recently shown computationally that vibrational entropy can drive phase transitions in materials such as [CH 3 NH 3 ]­PbI 3 or [NH 3 NH 2 ]­Zn­(HCOO) 3 . − …”

Band edge smearing due to compositional disorder in multi‐component d ‐dimensional alloys

“…These local compositional fluctuations create disorder potential that affects the energy spectrum in the form of band tails . The smearing of the band edges due to disorder potential can affect optoelectronic properties of devices based on classical III–V and II–VI semiconductors as well as bias energy spectra of modern perovskite materials suggested for photovoltaic applications .…”