Optical absorption of small silver clusters: Ag(n), (n=4-22)

Area of Science:

• * Physical Chemistry
• * Materials Science
• * Computational Chemistry

Background:

• * Understanding the optical properties of metal clusters is crucial for their application in nanotechnology.
• * Silver clusters (Ag(n)) exhibit unique electronic and optical behaviors that change with size.
• * Previous studies have explored various aspects of silver cluster properties.

Purpose of the Study:

• * To investigate the absorption spectra of silver clusters Ag(n) for n = 4-22.
• * To compare experimental results with theoretical calculations.
• * To determine the role of s- and d-electrons in the optical response of silver clusters.

Main Methods:

• * Experimental measurement of absorption spectra for silver clusters isolated in an Argon (Ar) matrix.
• * Theoretical calculations using time-dependent density functional theory (TD-DFT).
• * Analysis of molecular transitions to understand electronic contributions.

Main Results:

• * Experimental and calculated absorption spectra of Ag(n) clusters (4 ≤ n ≤ 22) were obtained and compared.
• * For small clusters (n ≤ 8), the s-electrons were identified as the primary contributors to the optical response.
• * For larger clusters (n > 8), d-electrons were found to play a significant role in optical excitations.

Conclusions:

• * The electronic configuration significantly influences the optical properties of silver clusters.
• * A size-dependent transition in electronic contributions (s- to d-electrons) governs the optical spectra of silver clusters.
• * The findings provide insights into the fundamental electronic structure and optical behavior of silver nanoclusters.