Electrical and optical properties of fluorine-doped ZnO thin films prepared by spray pyrolysis

• Published in: Thin solid films Vol. 333; no. 1; pp. 196 - 202
• Main Authors: Sanchez-Juarez, A, Tiburcio-Silver, A, Ortiz, A, Zironi, E.P, Rickards, J
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 23.11.1998; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Low-field transport and mobility; piezoresistance; Nuclear reaction; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optical properties of specific thin films; Other semiconductors; Physics; X-ray diffraction; Zinc oxide; X-ray diffraction; Zinc oxide; Nuclear reaction; Optical properties; Thin films; Zinc oxides; Energy gap; Inorganic compounds; Electrical conductivity; Refractive index; Transition element compounds; Fluorine additions; Doped materials; Experimental study; Carrier mobility; Carrier density
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(98)00851-7

Undoped and fluorine-doped ZnO thin films deposited by spray pyrolysis onto soda-lime glass substrates were electrically and optically characterized. Resistivities as low as 1×10 −1 Ω cm, Hall mobility as high as 10 cm 2/V per s and effective carrier concentration as high as 4×10 19 cm −3 have been obtained. Relative fluorine concentration was determined by the resonant nuclear reaction method. Electron concentrations due to the fluorine incorporation as an effective electrically active donor is always lower than fluorine contents on the films and in the starting solution. Average optical transmisttance on the whole visible range as high as 92% (substrate losses not included) have been obtained for the best conductive films. The refractive index of layers was found to increase with fluorine doping and substrate temperature. The fluorine incorporation, at ZnO thin films, results in a band gap widening effect.