Effects of Laser and Electron Beam Incidence on Semiconductor Materials: an ab initio Investigation

• Grant number: 24/19996-3
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Luis Antônio Cabral
• Grantee: Luis Antônio Cabral
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated researchers: Edison Zacarias da Silva ; Julio Ricardo Sambrano ; Von Braun Nascimento

Abstract

The focus of this research project is the study and control of structural and electronic properties of semiconductor materials due to the incidence of laser and electron beam. External disturbances can change the growth pattern andcontrol the defect density in semiconductor nanostructures, opening a wide field of investigations into the electronic structure of the irradiated materials, such as the emergence of magnetism in non-magnetic structures. The controlof electronic excitation and lattice heating through laser and electron beam allows modulating the band gap of the semiconductor, changing the luminescence center of the material according to the interest of studies and industrial applications, in which the relaxation channels tend to carry the nanostructure to the ground state. After a certain period of irradiation time, the formation and diffusion of nanoclusters through the material is observed, which move towards the surface of the irradiated material for their subsequent adsorption. The order-disorder relationship is observed for low radiation limits, while the greatest disorder is determined for high radiation values. Computational modeling at theatomistic scale based on density functional theory allows us to elucidate, predict and design new effects in the study of the incidence of external fields in semiconductor materials. Due to the lower mass of electrons in relation to nuclei, therapid response of electrons and holes in relation to nuclei can be simulated through finite temperature density functional theory, while the lattice heating is investigated through ab inito molecular dynamics. The high computational cost for simulating and understanding the effects of laser and electron beam incidence on semiconductors becomes a barrier to be overcome. The success previously obtained with these simulations allows us to continue investing in this model, in which silver-based semiconductor compounds will be studied firstly due to their applications in nanoscience and nanomedicine. (AU)