Formation of Metallic Ag on AgBr by Femtosecond Laser Irradiation

Abstract

Laser irradiation of materials induces changes in their structure and functional properties. In this work, lattice heating and electronic excitation on silver bromide (AgBr), provoked by femtosecond laser irradiation, have been investigated by finite-temperature density functional theory and ab initio molecular dynamics calculations by using the two-temperature model. According to our results, the electronic temperature of 0.25 eV is enough to excite the electrons from the valence to the conduction band, whereas 1.00 eV changes the structural properties of the irradiated AgBr material. Charge density simulations also show that an Ag clustering process and the formation of Br3− complexes take place when the electronic temperature reaches 2.00 eV and 5.00 eV, respectively. The present results can be used to obtain coherent control of the extreme nonequilibrium conditions due to femtosecond laser irradiation for designing new functional materials.

Keywords

• finite temperature-density functional theory
• <i>ab initio</i> molecular dynamics
• two-temperature model
• femtosecond laser irradiation
• AgBr
• clustering process