Structural correlations for increased FOM in Pb doped Zn2SnO4 nanostructured films for applications as transparent electrode

• Published in: Journal of alloys and compounds Vol. 900; p. 163531
• Main Authors: Arora, Isha, Natarajan, Vanasundaram, Sharma, Praveen Kumar
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.04.2022; Elsevier BV
• Subjects: Carrier density; Conductors; Figure of merit; Figure of merit (FOM); Nanostructure; Optoelectronic properties; Optoelectronics; Photoelectrons; Photovoltaic cells; Raman spectra; Raman spectroscopy; Refractivity; Sol-gel process; Spectrum analysis; Transparent conducting oxides (TCO’s); X-ray photoemission spectroscopy (XPS); Zinc stannate; Transparent conducting oxides (TCO’s); Optoelectronic properties; Figure of merit (FOM); Raman spectroscopy; Sol-gel process; X-ray photoemission spectroscopy (XPS)
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.163531

•Structure-property correlations for spin coated Zn2−xPbxSnO4 nanostructured films.•Polycrystalline cubic inverse spinel ZTO phase with dominance of T2 g(3) vibrational mode.•Relative change in contributions of Pb4+ and Pb2+ oxidation states in Pb doped ZTO system.•Maximum average transparency of 87% in 400–650 nm and refractive index of 1.6 at 500 nm for x = 0.08.•Maximal carrier density of 1020 cm−3 and Haacke’s Figure of merit of 1.1 × 10−3/ Ω for x = 0.08 suitable as transparent conductor. This work reports the detailed analysis of the structure and optoelectronic properties of spin coated Zn2−xPbxSnO4 nanostructured films. XRD studies reveal the polycrystalline cubic inverse spinel structure while Raman spectra show the dominance of T2 g(3) mode and decrease in intensity of A1 g mode with Pb doped ZTO films. X-ray photoelectron spectroscopy substantiates the dominance of atom in multiple charge states and their possible substitutions in the host lattice. The maximum average transparency of 87% in 400–650 nm spectral region for x = 0.08 sample while the decrease in optical gap from 4.32 to 4.14 eV with minimal value of 4.04 eV for x = 0.04 is found. The refractive index at 500 nm is calculated using Swanepoel’s method and found to decrease from 1.72 for ZTO and 1.59 for x = 0.08 sample. The carrier concentration increases from 1018 cm−3 for ZTO to 1020 cm−3 for x = 0.08 sample. The minimal value of electrical resistivity of 2.17 × 10−3 Ω-cm and maximal Haacke’s Figure of merit (FOM) of 1.1 × 10−3/ Ω is obtained for x = 0.08. These results are significant advancement to the development of ZTO based transparent conductors for highly efficient futuristic optoelectronics and photovoltaic devices.