Research paper Effects of morphology on the structural and photoluminescence properties of co-precipitation derived GdVO 4 :Dy 3+ Puja Kumari, J. Manam ⇑ Department of Applied Physics, Indian School of Mines, Dhanbad 826004, India article info Article history: Received 15 June 2016 In final form 7 September 2016 Available online 9 September 2016 abstract Herein, Dy 3+ doped GdVO 4 samples with various morphologies were prepared by the co-precipitation method at low temperature, and the effects of different morphologies on the structural and optical behaviors have been reported. The obtained samples were stabilized to the stable tetragonal structure. The IR and FESEM study were carried out to see the vibrational bonds position and surface morphology. At present PL, PLE, diffuse reflectance and decay curves have been discussed in detail. The morphology dependent photoluminescence studies were resulted to a suitable sample for the lighting and display applications. Ó 2016 Elsevier B.V. All rights reserved. 1. Introduction Inorganic luminescent phosphors doped by rare-earth ions have been extensively used in various applications, such as cathode ray tubes (CRTs), plasma display panels (PDPs), field emission displays (FEDs), and white-light emitting diodes (W-LEDs) [1–4]. Selection of proper host having absorption in ultra violet (UV) region and ability to sufficient energy transfer to the activator is necessary for synthesizing luminescent material. In these manners vana- dates, molybdates, tungstates, etc. have found huge attention because of their higher absorption in UV region and emission in blue region. Lanthanides have absorption in the blue region of elec- tromagnetic spectrum. The overlapping of host emission and lan- thanide absorption can lead to efficient photoluminescence (PL) emission [5,6]. Among the vanadates, YVO 4 and GdVO 4 are the most studied hosts. The crystallinity and morphology has a key role in optical behavior of the prepared phosphor. Gadolinium orthovanadate (GdVO 4 ) based nanomaterials are promising single phase candi- date that can have both magnetic and fluorescent properties. As GdVO 4 can be used as T 1 -positive contrast agents because Gd 3+ ions possess seven unpaired electrons which could efficiently alter the relaxation time of surrounding water protons [7]. Furthermore, GdVO 4 has been shown to be an efficient host for lanthanide ions- activated phosphors that can emit various colors with tuning of lanthanides. The photoluminescence emission from rare earth doped materials arises due to the transitions within the 4f n energy manifolds which are forbidden because of the electric dipole selec- tion rule but these are partially allowed due to the mixing of con- figurations having opposite parity. The synthesis method and nanoparticle formation condition also has a key impact on the flu- orescent properties of the material. Among the synthesis condi- tions pH also play an important role, as its alteration leads to change in surface morphology, the vibrational bands positions and hence luminous efficacy [8,9]. Kang et al. have studied the pH dependent drug release of GdVO 4 hollow sphere and its luminescent properties [10]. The effect of pH on morphology has also been studied by Le et al. for hydroxyapatite [11]. Wu et al. have also found morphological changes in Eu 3+ doped KCaY(PO 4 ) 2 with the variation of pH [12]. However all the studied have been focused on the preparation at low pH values. In this work first time the reports are been provided for GdVO 4 doped with Dy 3+ with varying pH values of the solution at the time of particle growth. Effect of this on morphological changes has been explained in detail and effect of these changes on structural and optical properties are also explained at their best levels. 2. Experimental GdVO 4 doped with Dy 3+ has been synthesized using co- precipitation method. Dy 3+ was taken as substitutional dopant in place of Gd 3+ . In a typical experiment, stoichiometric amount of precursors gadolinium oxide (Gd 2 O 3 ), dysporsium oxide (Dy 2 O 3 ) and ammonium meta vanadate (NH 4 VO 3 ) of high purity (99.99%) were taken. Oxide precursors were dissolved in a fixed amount of nitric acid followed by heating to form their nitrates separately. http://dx.doi.org/10.1016/j.cplett.2016.09.013 0009-2614/Ó 2016 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail addresses: pp.phy.ism@gmail.com (P. Kumari), jairam.manam@gmail. com (J. Manam). Chemical Physics Letters 662 (2016) 56–61 Contents lists available at ScienceDirect Chemical Physics Letters journal homepage: www.elsevier.com/locate/cplett