Nonlinear optical characteristics and photoluminescence of sprayed deposited ZnO:F thin films K. Bahedi a,b,⇑ , M. Addou c , A. Mrigal b , H. Cherrad b , Z. Soufiani d , S. Bayoud b , H. Fatouhi c , Z. El Jouad b , A. Ihlal a , H. Kirou a a Materials and Renewable Energies Laboratory, Ibn Zohr University, Faculty of Sciences, BP 8106 Dakhla, Agadir, Morocco b Optoelectronics and Physical Chemistry of Materiaux Laboratory, Ibn Tofail University, Faculty of Sciences, BP 133 14000 Kenitra, Morocco c Materials and Valorizations of Natural Resources Laboratory, Abdelmalek Essaadi University, Tanger, Morocco d Hassan II University, Faculty of Science and Technology Mohammedia, Morocco article info Article history: Received 14 June 2019 Received in revised form 7 July 2019 Accepted 10 July 2019 Available online xxxx Keywords: ZnO Fluorine Spray pyrolysis NLO Susceptibility Thin films abstract This paper reports the influence of fluorine on the third order nonlinear optical in zinc oxide (ZnO) thin films grown by spray pyrolysis method on heated glass substrates at 450 °C. The ZnO:F films are polycrys- talline with the hexagonal wurtzite structure and a preferred orientation with the c axis perpendicular to the substrates. The optical nonlinearity was investigated employing the third harmonic generation (THG) technique. The nonlinear optical susceptibility was found to be related to the films stress. Photoluminescence (PL) emission characteristics confirm the improvement of the nonlinear optical susceptibility. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Confer- ence on Plasma and Energy Materials ICPEM2019. 1. Introduction An important demand of too fast devices that can make diag- nostics at the height and the point as well as increasing the infor- mation storage capacity has been an active field of great interest in this last decade. Lasers provide a solution to these problems of speed, diagnostic and storage. So it is necessary to look for laser emissions in the low wavelengths especially around the Ultra Vio- let. Nonlinear optics is the basic principle with which such wave- lengths can be generated. The Materials with good response nonlinear optical properties allow the production of harmonics (multiple frequencies of the initial frequency, so reduced wave- lengths) to an initial laser excitation that emits in the infrared (like YAG lasers). ZnO is a transparent conducting oxide with a strong third order nonlinear optical susceptibility [1–3] and can be used for various applications like optical information storage, optical switching, optical waveguides, high-speed optical communication...ZnO is known to be an n-type semiconductor with a wide band gap 3.35 eV at room temperature. The addition of impurities to a ZnO thin film induces changes in the physical and chemical properties. The choice of the dopant element depends on its electronegativity and ionic radius [4]. Many works done on doping of ZnO thin films are available, such as those doping with F [5], Nd [6], Al [7], Li [8], In [9–10], and Ga [11]. The case of fluorine doped ZnO thin films is an example for this. The fluorine is a promising anion doping can- didate because its ionic radius (1.36 Å) is similar to that of oxygen (1.40 Å) [12]. The high size-compatibility of their ionic radius effec- tively reduces the lattice distortion compared with metal cation dopants. In addition, F can occupy the VO sites in the ZnO atomic struc- ture to form the stronger zinc–fluorine (Zn–F) bonds (364 kJ/mol) compared with the zinc–oxygen (Zn–O) bonds (284 kJ/mol) [13], which contributing to the enhancement of thermal stability. Moreover, the substitution of an oxygen ion (O 2À ) with a fluo- rine ion (F À ) supplies a free electron because of the difference in the electrovalence of O 2À and F À [14], resulting in the increase in the conductivity. Recently the third order NLO properties in ZnO-based thin films have been reported to be influenced by several parameters [15,16]. In this work we reported the cubic NLO responses v (3) of ZnO:F thin films deposited on glass substrates using a spray pyrolysis https://doi.org/10.1016/j.matpr.2019.07.623 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Plasma and Energy Materials ICPEM2019. ⇑ Corresponding author. Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: K. Bahedi, M. Addou, A. Mrigal et al., Nonlinear optical characteristics and photoluminescence of sprayed deposited ZnO:F thin films, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.07.623