White-light emission from annealed ZnO:Si nanocomposite thin films

• Published in: Journal of luminescence Vol. 132; no. 7; pp. 1744 - 1749
• Main Authors: Shabnam, Kant, Chhaya Ravi, Arun, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2012; Elsevier
• Subjects: Annealing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Emission analysis; Exact sciences and technology; Nanocomposites; Nanocrystals and nanoparticles; Nanomaterials; Nanostructure; Nanostructures; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Oxides; Photoluminescence; Physics; Silicon; Thin films; White light; Zinc oxide; Oxides; Nanostructures; Nanocomposites; Photoluminescence; Nanocluster; Raman spectra; Annealing; Heat treatments; Thin films; Line intensity; Solid clusters; Line broadening; Ultraviolet radiation; Zinc oxide; Silicon; Vacuum evaporation; X-ray photoelectron spectra
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2012.01.051

As grown ZnO:Si nanocomposites of different compositional ratios were fabricated by thermal evaporation techniques. These films were subjected to post-deposition annealing under high vacuum at a temperature of 250°C for 90min. The photoluminescence (PL) spectra of annealed samples have shown marked improvements both in terms of intensity and broadening. Structural and Raman analyses show formation of a Zn–Si–O shell around ZnO nanoclusters wherein on heating Zn2SiO4 compound forms resulting in huge UV, orange and red peaks at 310, 570 and 640nm in PL. The new emissions due to Zn2SiO4 completes white light spectrum. The study not only suggests that 1:2 ratio is the best suited for material manipulation but also shows process at the interface of ZnO nanoclusters and silicon matrix leads to new PL emissions. ► ZnO:Si nano-composites films were annealed under high vacuum. ► The photoluminescence spectra of these show broadening. ► New peaks formed due to a Zn–Si–O shell around ZnO clusters.