Solid State Communications 139 (2006) 479–484 www.elsevier.com/locate/ssc Optical and structural parameters of the ZnO thin film grown by pulsed filtered cathodic vacuum arc deposition Ebru S ¸enadım, Sıtkı Eker, Hamide Kavak ∗ , Ramazan Esen Physics Department, Cukurova University, 01330, Adana, Turkey Received 31 May 2006; received in revised form 19 June 2006; accepted 1 July 2006 by H. Akai Available online 18 July 2006 Abstract Transparent conductive ZnO film was deposited on glass substrate by pulsed filtered cathodic vacuum arc deposition (PFCVAD). Optical parameters such as absorption coefficient α, the refractive index n, energy band gap E g and dielectric constants have been determined using different methods. Kramers–Kronig and dispersion relations were employed to determine the complex refractive index and dielectric constants using reflection data in the ultraviolet–visible–near infrared regions. The spectra of the dielectric coefficient were used to calculate the energy band gap and the value was 3.24 eV. The experimental energy band gap was found to be 3.22 eV for 357 nm thick ZnO thin film. The envelope method was also used to calculate the refractive index and the data were consistent with K–K relation results. The structure of the film was analyzed with an x-ray diffractometer and the film was polycrystalline in nature with preferred (002) orientation. c  2006 Elsevier Ltd. All rights reserved. PACS: 78.20-e; 78.20.Ci; 78.20.Bh; 81.05.Dz; 81.15.Ef Keywords: A. ZnO thin film; B. Pulsed filtered cathodic vacuum arc deposition; B. Structural properties; D. Optical properties 1. Introduction Transparent conducting oxide (TCO) films have found extensive applications in optoelectronic devices [1] (for example, solar cells [2], liquid crystal displays, heat mirrors and multiplayer photothermal conversion systems [3]). Zinc oxide has attracted attention as a transparent conducting oxide because of its (i) large band gap (3.3 eV) [4], (ii) high conductivity, (iii) ease in doping, (iv) chemical stability in hydrogen plasma [5], (v) thermal stability when doped with III group elements [6], and (vi) abundance in nature and nontoxicity. In addition to potential use as transparent conducting oxide in optoelectric devices, ZnO thin films also find application as gas sensors [6], because of their high electrical resistivity. Several deposition techniques are used to grow zinc oxide (ZnO) thin films. These include chemical vapor deposition ∗ Corresponding address: Cukurova University, Science and Art Faculty, Physics Department, TR01330/Adana, Turkey. Tel.: +90 322 3386801; fax: +90 322 3386070. E-mail address: hkavak@cu.edu.tr (H. Kavak). (CVD) [7,8], magnetron sputtering [9–12], cathodic vacuum arc deposition (CVAD), spray pyrolysis [13,14], and pulsed laser deposition (PLD) [15,16]. The filtered cathodic vacuum arc, another energetic deposition technique, has recently received little attention for the preparation of ZnO films. Naoe and Nakagawa prepared ZnO films at temperature 600 ◦ C by a vacuum arc without macroparticle filtering [17]. Takikawa et al. deposited c-axis oriented ZnO films by a simple shielded vacuum arc without external heating in the pressure range of 1×10 −3 –4×10 −2 Torr, where the distance between the cathode and substrate was 20 cm [18]. In comparison with other techniques, pulsed filtered cathodic vacuum arc deposition (PFCVAD) provide high density, high adhesion, excellent coating uniformity of thin films at low deposition temperatures [19]. Besides these advantages nearly 100% ionization of the cathode materials in the plasma means that the impact energy of the depositing ions at the growth surface can be readily controlled using electric fields. Their high-energy plasma plume will readily ionize most background gases. These features make the pulsed cathodic vacuum arc an ideal source for the production of metal oxides and nitrides [19]. And also the PFCVAD technique provides 0038-1098/$ - see front matter c  2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.ssc.2006.07.001