High Band Gap Nanocrystalline Tungsten Carbide (nc-WC) Thin Films Grown by Hot Wire Chemical Vapor Deposition (HW-CVD) Method

Автор(ы) Bharat Gabhale1 , Ashok Jadhawar1 , Ajinkya Bhorde1 , Shruthi Nair1 , Haribhau Borate1 , Ravindra Waykar1 , Rahul Aher1 , Priyanka Sharma1, Amit Pawbake1, Sandesh Jadkar2

1School of Energy Studies, Savitribai Phule Pune University, 411 007 Pune, India

2Department of Physics, Savitribai Phule Pune University, 411 007 Pune, India

Е-mail sandesh@physics.unipune.ac.in
Выпуск Том 10, Год 2018, Номер 3
Даты Получено 01.03.2018; в отредактированной форме 09.06.2018; опубликовано online 25.06.2018
Ссылка Bharat Gabhale, Ashok Jadhawar, Ajinkya Bhorde, et al., J. Nano- Electron. Phys. 10 No 3, 03001 (2018)
DOI https://doi.org/10.21272/jnep.10(3).03001
PACS Number(s) 81.15.Cd, 81.07.Bc
Ключевые слова WC films, HW-CVD (2) , Low angle XRD (2) , Raman spectroscopy (18) , XPS (3) .

In present study nanocrystalline tungsten carbide (nc-WC) thin films were deposited by HW-CVD using heated W filament and CF4 gas. Influence of CF4 flow rate on structural, optical and electrical properties has been investigated. Formation of WC thin films was confirmed by low angle XRD, Raman spectroscopy and x-ray photoelectron spectroscopy (XPS) analysis. Low angle XRD analysis revealed that WC crystallites have preferred orientation in (101) direction and with increase in CF4 flow rate the volume fraction of WC crystallites and its average grain size increases. Formation of nano-sized WC was also confirmed by transmission electron microscopy (TEM) analysis. UV-Visible spectroscopy analysis revealed increase in optical transmission with increase in CF4 flow rate. The WC film deposited for 40 sccm of CF4 flow rate show high transparency (~ 80-85 %) ranging from visible to infrared wavelengths region. The band gap shows increasing trend with increase in CF4 flow rate (3.48-4.18 eV). The electrical conductivity measured using Hall Effect was found in the range ~ 103-141 S/cm over the entire range of CFflow rate studied. The obtained results suggest that these wide band gap and conducting nc-WC films can be used as low cost counter electrodes in DSSCs and co-catalyst in electrochemical water splitting for hydrogen production.

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