arXiv subjects

Sreejith Pallikkara Chandrasekharan

Publications and source records attributed to Sreejith Pallikkara Chandrasekharan.

4 recordsLinked to original sources

arXiv2026

III-V antiphase boundaries are not generated by Si or Ge substrate step edges

We critically review recent experimental and theoretical advances on the valence- and structure-mismatched heteroepitaxy of III-V semiconductors on group-IV substrates. We examine key aspects including wetting behavior, atomic configurations at the hetero-interface, substrate passivation, and the stability of antiphase boundaries (APBs). By synthesizing these findings with pioneering studies, we propose a refined description of antiphase boundaries formation. Our analysis shows that hetero-interface formation is dictated by substrate terrace reconstruction, demonstrating that APBs are not generated at monoatomic step edges. This generalized III-V/IV growth framework provides new insights for the integration of III-V semiconductors on group-IV platforms and, more broadly, for valence-mismatched heteroepitaxy.

cond-mat.mtrl-sci↗

arXiv2025

Efficient absolute interface energy calculations for heterostructures: Synergy between localized basis sets and surface passivation techniques

Heterostructures combining diverse physico-chemical properties are increasingly in demand for a wide range of applications in modern science and technology. However, despite their importance in materials science, accurately determining absolute interface energies remains a major challenge. Here, we present a computationally efficient framework for determining interface energies by incorporating a surface passivation technique, demonstrated using pseudo H passivation with a localized basis set method and an explicit chemical potential. This framework is applied to calculate absolute interface energies and analyze the electronic properties of quasi lattice matched and lattice mismatched III and V on Si interfaces, with results compared to conventional reconstructed surface calculations. By combining localized basis sets with surface passivation techniques, this framework allows for accurate estimation of absolute interface energies in heterogeneous material systems. This approach effectively addresses issues associated with surface reconstructions while significantly reducing computational costs within the framework of density functional theory, and moreover offers considerable potential for calculating interface energies across diverse material systems.

cond-mat.mtrl-sci↗

arXiv2025

Full ab initio atomistic approach for morphology prediction of hetero-integrated crystals: A confrontation with experiments

Here, we propose a comprehensive first-principle atomistic approach to predict the Wulff-Kaischew equilibrium shape of crystals heterogeneously integrated on a dissimilar material. This method uses both reconstructed surface and interface absolute energies, as determined by density functional theory, to infer the morphology and wetting properties of Volmer-Weber islands over the whole range of accessible chemical potentials. The predicted equilibrium shapes of GaP crystals heterogeneously grown on Si, are found to be in good agreements with experimental observations performed by Transmission Electron Microscopy. Such method provides a tool for optimization of hetero-structured, multifunctional and smart materials and devices.

cond-mat.mtrl-sci↗

arXiv2025

Computational assessment of non-polar and polar GaP terminations for photoelectrochemical water splitting

With photoelectrochemical water splitting being one of the most promising approaches for clean energy production and storage, the search for efficient photoelectrode materials is greater than ever. Gallium phosphide (GaP) is a well-established semiconductor with suitable band edge positions that has already been successfully employed in photoelectrochemical solar cells. However, to utilize it as efficiently as possible, a proper understanding of its properties when interfaced with water is required, and this is currently lacking. In this work we use ab initio molecular dynamics simulations to study the properties of the aqueous interfaces of various GaP non-polar (110) and polar (001) terminations. We calculate their band alignment with respect to the standard hydrogen electrode potential and investigate their interfacial structural properties. Based on these properties we assess the capability of the various terminations to catalyze the reactions associated with water splitting and propose approaches for improving the performance of GaP for application in PECs.

cond-mat.mtrl-sci↗