LSPR mediated improved upconversion emission on randomly distributed gold nanoparticles arrays
In this article, authors report on the plasmonic upconversion (UC) emission enhancement of Gd2O3: Er3+/Yb3+ thin films grown on randomly distributed gold nanoparticles (AuNPs) on glass. The AuNPs were prepared by thermal annealing of a gold thin film on the glass substrate at 500 oC for 2 hours. Gd2O3: Er3+/Yb3+ thin films were deposited over the AuNPs by using the pulsed laser deposition technique. The prepared plasmonic films have shown strong UC emission intensities with comparison to the reference Gd2O3: Er3+/Yb3+ thin film. This enhanced UC intensity was assumed to be due to the strong optical field associated with the localized surface plasmon resonance (LSPR) and strong light scattering from the AuNPs. A theoretical simulation based on a finite element method was performed to understand the nature of the optical field confined in the AuNPs present in the Gd2O3: Er3+/Yb3+ thin film. This study is believed to be beneficial for several applications such as thin film based infrared detector and high efficient photovoltaic devices.