Habib M Pathan
Articles written in Bulletin of Materials Science
Volume 36 Issue 7 December 2013 pp 1177-1185
Hydrogenated amorphous silicon carbide (a-SiC:H) thin films were prepared using pure silane (SiH4) and ethane (C2H6), a novel carbon source, without hydrogen dilution using hot wire chemical vapour deposition (HW-CVD) method at low substrate temperature (200 °C) and at reasonably higher deposition rate (19.5 Å/s < 𝑟d < 35.2 Å/s). Formation of a-SiC:H films has been confirmed from FTIR, Raman and XPS analysis. Influence of deposition pressure on compositional, structural, optical and electrical properties has been investigated. FTIR spectroscopy analysis revealed that there is decrease in C–H and Si–H bond densities while, Si–C bond density increases with increase in deposition pressure. Total hydrogen content drops from 22.6 to 14.4 at.% when deposition pressure is increased. Raman spectra show increase in structural disorder with increase in deposition pressure. It also confirms the formation of nearly stoichiometric a-SiC:H films. Bandgap calculated using both Tauc’s formulation and absorption at 104 cm-1 shows decreasing trend with increase in deposition pressure. Decrease in refractive index and increase in Urbach energy suggests increase in structural disorder and microvoid density in the films. Finally, it has been concluded that C2H6 can be used as an effective carbon source in HW-CVD method to prepare stoichiometric a-SiC:H films.
Volume 38 Issue 2 April 2015 pp 493-498
The preparation of crystalline antimony sulphide (Sb2S3) by chemical route at room temperature was reported in this paper. The structural, morphological and optical properties of as-synthesized sample were system- atically investigated. X-ray diffraction (XRD) analysis confirms the orthorhombic crystal phase for prepared Sb2S3. Scanning electron microscope (SEM) images show uniform, dense spherical morphology having diameter around 200–220 nm. Energy band gap calculated from optical absorption spectra was observed around 2.17 eV. Contact angle measurement confirms the hydrophilic nature of the deposited film. The photoluminescence analysis shows low green luminescence as well as Stoke's shift for as-prepared Sb2S3. The nanostructured solar cell is fabricated for energy harvesting purpose with Sb2S3-sensitized SnO2 photoanode and polysulphide electrolyte. The solar cell with FTO/SnO2/Sb2S3 photoanode shows 𝑉OC ∼ 240 mV, 𝐽sc ∼ 0.640 mA cm−2 and FF ∼ 35%. The working mechanism and energy level diagram of Sb2S3/SnO2 system have been discussed.
Volume 42 | Issue 6
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