Preparation and characterization of luminescent YPO4: Eu3+ thin films using sol gel spin coating method

• Published in: Thin solid films 2020-01, Vol.694, p.137738, Article 137738
• Main Authors: Benharrat, L., Guerbous, L., Bradai, D., Boukerika, A., Manseri, A., Selmi, N., Rahal, B., Hamroun, M.S.E.
• Format: Article
• Language: English
• Subjects: Europium-doped yttrium phosphate; Luminescence; Sol gel deposition; Spin coating; Thin films
• ISSN: 0040-6090
• DOI: 10.1016/j.tsf.2019.137738

•YPO4: Eu3+ orange-red nanophosphors are prepared by sol-gel spin-coating.•Effect of solutions with different sol gel routes used to prepare powders and films.•Sample-solution and form effects on morphology and luminescence were investigated.•R/O and light extraction ratios for each solution samples were discussed. Orange-red color emission obtained from YPO4: 5 at.% Eu3+ nanocrystalline thin films are prepared by spin coating sol gel route. The thorough study of two different sol gel routes and their effect on structural and luminescent properties of YPO4:Eu3+are investigated. Prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy and photoluminescence spectroscopy. This work demonstrated that the use of relatively stronger solvents during the sol gel route favorize the dissolution of oxide salts’ precursors within solutions and enhance their stabilization. XRD analysis indicated the formation of nanopowders and nanocrystalline thin films. Structural properties showed a strong correlation between the parameters related to samples’ solution and form. All samples showed uniform morphology with different sizes and shapes of particles depending on the solution and the form of the nanophosphor. Under UV excitation, YPO4: Eu3+powders and thin films exhibited, orange-red color emissions assigned to 5D0 → 7FJ (J=1,2,3 and 4) intraconfigurational transitions. Asymmetry ratio (R/O) analysis showed that Eu3+ in YPO4 host matrix tends to occupy high symmetry sites when prepared as thin films compared to powders. The thin film with better crystallinity and bigger particle sizes exhibited better emission efficiency but low symmetry of crystal field near Eu3+ ions (high R/O) and low light extraction ratio.