• S VALANARASU

Articles written in Bulletin of Materials Science

• Effect of Nd doping on structural and opto-electronic properties of CdO thin films fabricated by a perfume atomizer spray method

A perfume atomizer-assisted spray pyrolysis method was employed to fabricate undoped and neodymium (Nd)-doped cadmium oxide (CdO) thin films. X-ray diffraction results reveal that all the films are polycrystalline witha cubic structure with a preferential orientation along the (200) direction. Scherrer’s formula was used to calculate the crystallite size of Nd-doped CdO films. Energy dispersive spectroscopy results show that Cd, Nd and O elements are present in Nd-doped CdO thin films. The optical absorption of the doped films is increased along with increasing Nd-doping level. The prepared CdO thin films have a high absorption coefficient in the visible region and the optical band gap is decreased on increasing Nd doping content. The electrical carrier concentration (n) of the deposited films is increased with increasing Nd doping concentration. Photoconductivity studies of a nanostructured Al/Nd–n-CdO/p-Si/Al device showed a non-linear electric characteristics indicating diode-like behaviour. Prepared Nd:CdO films could increase the photo-sensing effect ofthis n-CdO/p-Si heterostructure. These Nd-doped CdO thin films may open a new avenue for photodiode application in near future.

• Effect of carrier gas pressure on structural, optical and photovoltaic properties of tin sulphide thin films prepared by nebulizer spray pyrolysis method

Tin sulphide (SnS) thin films deposited using nebulizer spray pyrolysis technique by changing pressure (0.1, 0.15, 0.2 and 0.25 Pascal) at 350$^{\circ}$C and their characterization are reported. The influence of carrier gas pressure on structural, morphological, optical and electrical properties of the film are determined using X-ray diffraction (XRD), energy-dispersiveX-ray, atomic force microscopy, UV–Vis spectrophotometry and Hall effect measurement. Structural parameters such as pole density, orientation factor, crystallite size, micro strain and dislocation density were analysed using XRD data. The scanning electron microscopy studies display superior morphology and surface roughness of the films which were found to increase with pressure. Optical studies on the films revealed a variation in band gap from 1.78 to 1.66 eV for were the raise of pressure from 0.1 to 0.2 Pa. A single strong emission peak at about 825 nm is observed in photoluminescence spectra with enhanced intensity which may be attributed to near band edge emission. Grown SnS thin film exhibits p-type conductivity, which was confirmed from the Hall effect measurement. The low resistivity and higher carrier concentration are found tobe 0.235 $\Omega$cm and $5.04 \times 1018$ cm$^{−3}$, respectively. These properties were then correlated with the deposition parameters. Furthermore, to study the photovoltaic properties of SnS thin films, a heterojunction solar cell FTO/n-CdS/p-SnS/Al was fabricated showing conversion efficiency of 0.16%.

• # Bulletin of Materials Science

Volume 44, 2021
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020