Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: www.elsevier.com/locate/jalcom Novel p-type Ag-WO 3 nano-composite for low-cost electronics, photocatalysis, and sensing: synthesis, characterization, and application Lubna Aamir Department of Physics, College of Science for Girls, University of Hail, PO Box No. 2440, Ha'il 8145, Saudi Arabia article info Article history: Received 20 August 2020 Received in revised form 4 November 2020 Accepted 24 November 2020 Available online 26 November 2020 Keywords: Composite materials Heterojunctions Nanostructured materials Semiconductors Chemical synthesis Optical properties abstract Semiconductor–metal nanocomposites provide a simple and convenient way to tailor the properties of semiconductors and promote various properties and photoinduced processes like photovoltaic, photo- sensing, and photocatalysis. This article provides a detailed study on the facile synthesis and structural, optical, and electrical characterization of novel p-type silver-tungsten oxide (Ag-WO 3 ) nanocomposite using co-precipitation technique. Results indicate that it has an indirect bandgap of 2.9 eV and possesses excellent charge separation capability, as established by photoluminescence and impedance spectroscopy analysis. TEM and AFM results show the formation of WO 3 nano-plates with side length ranging from 10 nm to 25 nm, with the presence of silver nanoparticles (dimension 10–12 nm) either at its center or at the edges. P-type conductivity in the synthesized composite is investigated using PL analysis, which revealed that silver serves as a deep acceptor with acceptor level 1.4 eV above the valance band. To further demonstrate the capability of synthesized Ag-WO 3 in electronics, the current–voltage graph of Ag-WO 3 /Ag Schottky junction with knee voltage 0.59 V is also summarized, which suggest that Ag-WO 3 is an effective p-type semiconductor for electronic application too. This study provides new insight into the fabrication and practical application of Ag-WO 3 nanocomposite to produce efficient low cost electronic, sensing, and photocatalytic devices. © 2020 Elsevier B.V. All rights reserved. 1. Introduction Transition metal oxide semiconductors represent a large family of materials possessing diverse applications. These semi- conductor–metal nanocomposites offer an exciting and convenient way to create new materials with specified optical, electrical, or catalytic properties. Such materials could be employed for various potential applications in areas of optoelectronics, photocatalysis, plasmonics, and sensing [1]. Moreover, modification of semi- conductor by incorporation of noble metal improves charge se- paration and promotes inter-facial charge-transfer processes. This is due to charge accumulation in the metal layer, which results in fermi-level equilibration raising the quasi-Fermi level of the com- posite close to the conduction band level of the oxide semiconductor [1]. Such materials exhibit increased photo efficiency due to a re- duction in the electron-hole recombination rate and their absorption is broadened to the visible region of solar spectra due to the plas- monic effect created by metal nanoparticles [2–10]. Metal nano- particle in oxide semiconductors also found to increase the sensitivity and reduce the response and recovery time of gas sen- sors [11–17]. Among various transition metal oxides, tungsten oxide (WO 3 ) an n-type semiconductor, has attracted the interest of the scientific community due to its technological applications. Its bandgap is in the range of 2.6–3.0 eV [18]. Tungsten oxide shows several out- standing properties like electrochromic [19], gaschromic [20], pho- tochromic [21], gas sensor [22], photocatalyst [23], and photovoltaic [24]. However, Ag-doped/loaded WO 3 tungsten oxide had shown better electronic, photocatalytic, and sensing properties as compared to pristine WO 3 [25–27]. Various methods like sol-gel [28], chemical precipitation, hy- drothermal process, sputtering technique [29–31], and microwave irradiation [32] had been used to produce WO 3 [28] with various morphologies, such as nanoparticles, nanorods, and nanosheets [32–34]. Most of the methods reported here either produces oxygen- deficient WO 3−x / pristine WO 3 or Ag-doped WO 3 with n-type con- ductivity. Hardly any work reported the synthesis of p-type Ag-WO 3 nanocomposite and discussed its optical and electrical properties along with its practical application in electronics. The present re- search provides a complete study on the synthesis, characterization, and electronic application of p-type Ag-WO 3 having excellent charge https://doi.org/10.1016/j.jallcom.2020.158108 0925-8388/© 2020 Elsevier B.V. All rights reserved. ]] ]] ]]]]]] E-mail address: l.hashmi@uoh.edu.sa. Journal of Alloys and Compounds 864 (2021) 158108