Orientation-dependent epitaxial growth of GaAs heterojunction thin films: molecular dynamics insights into interfacial structures and crystallization behavior

Abstract Gallium arsenide heterojunction thin films are essential for high-frequency devices yet face challenges such as dislocation formation and phase mixing. This study employs molecular dynamics simulations to investigate the deposition of GaAs films across a wide temperature range and multiple crystallographic orientations. Unlike previous GaAs MD studies focused on limited orientations or narrow temperature windows, we systematically explore coupled temperature–orientation effects on phase transition dynamics and defect evolution. Results reveal that higher deposition temperatures significantly enhance structural ordering, yielding notable improvements in surface smoothness, atomic layer density, and energy stability compared to low-temperature deposits. These insights provide fundamental guidance for tailoring GaAs heterostructures in applications such as quantum dot lasers and photoelectrochemical catalysts.