Investigations of the physical behavior of novel polymorphs of indium phosphide from a first-principles perspective

Abstract

Polymorphism has been recognized as a useful tool to govern the behavior of solid materials for different technological applications. In this work, we present new polymorphs of Zinc-Blende (zb) Indium phosphide (InP) in Beryllium Oxide (β-BeO)-, Wurtzite (wz)-, and Silicon Carbide (SiC)-phases and explore their physical behavior from the first-principles perspective. These new polymorphs of InP exhibit hexagonal symmetry where the In 3+ and P 3− atoms exhibit tetrahedral coordination similar to zb-phase. The lack of imaginary frequencies in the phonon dispersions calculated for the novel InP polymorphs indicates their adequate dynamical stability. Moreover, the new polymorphs exhibited the cohesive energy comparable to that of the zb-phase of InP which indicated them thermodynamically as stable as the zb-phase of InP. The zb-polymorph, wz-polymorph, β-BeO-polymorph, and SiCpolymorph of InP exhibited direct bandgaps of magnitude 1.33, 1.32, 1.47, and 1.31 eV, respectively. The optical absorption by these novel polymorphs approaches to ~10 6 cm −1 in the visible (VI) part of the electromagnetic spectrum that are further evolved to 1.50 × 10 6 cm −1 , 1.61 × 10 6 cm −1 , 1.62 × 10 6 cm −1 , and 1.71 × 10 6 cm −1 for zb-polymorph, wzpolymorph, β-BeO-polymorph, and SiC-polymorph of InP respectively in the ultraviolet (UV) range. Such high absorption of light points to their potential photovoltaic applications. They also exhibit transparent nature for infrared (IR), VI, and a wide range of UV light that may find interesting applications in optoelectronics. The phase transition of InP at moderate pressure indicates that novel stable polymorphs of InP with interesting features can be accordingly developed for any desired technological application.

First-Principles Investigations of the Physical Properties of Experimentally Feasible Novel Aluminum Nitride Polytypes

“…Over the past few decades, semiconductor materials have attracted substantial attention due to their remarkable physical properties, making them adaptable to many modern technological applications. − Of this large family, group III nitrides, particularly AlN, are characterized by a high melting point, high thermal conductivity, good dielectric strength, high degree of hardness, and direct wide band gap. These characteristics make AlN a suitable material for microelectronic substrate applications, short-wavelength light-emitting diodes, laser diodes, and optical detectors, as well as for high-temperature, high-power, and high-frequency devices. − Consequently, extensive research has been conducted to characterize, as precisely as possible, the essential optical and electronic properties of AlN, which are of primary importance, as well as its mechanical and structural response. − In contrast to the zincblende (ZB), wurtzite (WZ), and rock salt (RS) phases, no comprehensive experimental or theoretical investigation has been conducted on the polytypism of AlN.…”