Nanocomposites and nanomaterials

Pulse laser deposited vanadate nanoparticles on glass and silicon substrates
Chukova O.1,  Nedilko S.A.1,  Nedilko S.G.1, Slepets A.1,  Voitenko T.1, Androulidaki A.2, Manousa A.2, Papadopoulos A.2, Savva K.2, Stratakis E.2
1 Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, Kyiv 01601, Ukraine. E-mail: chukova@univ.kiev.ua
2 Institute of Electronic Structure & Laser (IESL) of Foundation for Research & Technology Hellas (FORTH), Heraklion 711 10 Crete, Greece

Vanadate compounds are widely used matrices for luminescent rare earth (RE) ions dopants as they satisfy high efficiency of excitation of activator through the matrix. A wide range of possible applications of vanadate nanoparticles have attracted significant research efforts to development of new vanadate compositions with improved characteristics depending on requirements of various practical tasks. Studying the Eu3+-activated LaVO4 vanadate nanoparticles, we have achieved increase of emission intensity in 10 times using various synthesis conditions. The best intensity characteristics were achieved for the La1-xEuxVO4 nanoparticles synthesized by sol-gel method. Also we have developed vanadate nanoparticles with enchanced light harvesting from violet spectral range using heterovalence substitutions of RE ions with alkali earth cations. The next important task is to to save the obtained high optical characteristics of oxide nanoparticles under their deposition onto various substrates.
In the present work we report results of experiments with pulsed laser deposition (PLD) of the RE3+-activated LaVO4 vanadate nanoparticles on glass and silicon substrates. The applied vanadate nanoparticles were synthesized by aqueous nitrate-citrate sol-gel method using citric acid as a complexion agent. The deposition of nanoparticles was carried out using KrF excimer laser with λgen = 248 nm. The PLD process of the LaVO4 nanoparticles was not reported previously. Therefore, various experimental attempts were carried out in order to find optimal experimental conditions such as pulse power, repetition rate, and deposition duration.
SEM images, luminescence properties, UV-Vis reflection and absorption spectra of the obtained samples were investigated. The conclusion was made about favorable conditions for pulsed laser deposition of vanadate nanoparticles on glass and silicon substrates.