Effect of annealing on the stoichiometry and plasmonic properties of PLD nanostructured semi-transparent copper thin film using BEMA
- Resource Type
- Original Paper
- Authors
- Kesarwani, Rahul; Khare, Alika
- Source
- Journal of Materials Science: Materials in Electronics. 33(23):18209-18219
- Subject
- Language
- English
- ISSN
- 0957-4522
1573-482X
The plasmonic nature of Cu nanoparticles embedded in the glass is characterized and its dependence on annealing temperature and deposition time is reported. The nanostructured copper metallic thin films were fabricated onto the glass substrate via PLD technique at room temperature for the duration of 4, 6 and 8 min and then all these samples were gradually annealed up to 400 °C in a step of 100 °C for 4 h at each temperature. The size of the nanoparticles was observed to be varying from ~ 5 to 38 nm with the increase in the deposition time for as deposited (unannealed) films whereas that of the finally annealed films from 288 to 38 nm. The absorption spectra of as-deposited films didn’t display any plasmonic peak while the gradually annealed film exhibited both longitudinal and transverse plasmonic peaks. The Bruggeman effective medium approximation (BEMA) theory is applied on the spectroscopic ellipsometry spectra to examine the composition and plasmonic nature of the nanostructured Cu thin film. From the BEMA analysis, it was revealed that as-deposited films fitted well to the two oscillators (one Lorentz and one Gauss) dispersion model whereas that of gradually annealed films satisfied the four oscillators (one Lorentz and three Gauss) model. The as-deposited films exhibited the presence of large percentage of voids which diminished after final annealing to 400 °C. The percentage composition of Cu NP and Cu2O and the plasmonic peak were observed to be dependent on deposition time as well as annealing.