Article
Materials Science, Multidisciplinary
J. Vivekanandan, K. S. Usha, R. Sivakumar, C. Sanjeeviraja
Summary: In this study, mixed nickel-tungsten oxide thin films with different tungsten oxide concentrations were deposited using the RF sputtering technique. The properties of the films, such as transmittance, energy bandgap, and refractive index, were found to change with the concentration of tungsten oxide. The films also exhibited good characteristics for electrochromic and optoelectronic device fabrications.
Article
Materials Science, Multidisciplinary
K. S. Usha, R. Sivakumar, C. Sanjeeviraja, J. Vivekanandan
Summary: Thin films of nickel oxide (NiO) were prepared by RF magnetron sputtering at different substrate temperatures, and the effects of temperature on their structural, morphological, optical, and vibrational properties were investigated. It was found that an increase in substrate temperature led to higher crystallinity and smoother surface morphology of the NiO films. The optical transmittance and bandgap of the films also varied with substrate temperature. The optical and dispersion energy parameters of NiO films were affected by temperature as well. The results suggest the potential application of NiO films in optoelectronic and electrochromic devices.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Amar Kamal Mohamedkhair, Qasem Ahmed Drmosh, Mohammad Qamar, Zain Hassan Yamani
Summary: Tungsten oxide (WO3) thin films were prepared by DC reactive sputtering magnetron method, and their band gap was controlled by post-annealing temperature to enhance photoelectrocatalytic activity; films heated under air exhibited better performance; maximum photocurrent was observed at a film thickness of approximately 150 nm.
Article
Materials Science, Multidisciplinary
M. Osiac, V. Satulu, M. Jigau, I. Tirca, I. R. Tudorascu
Summary: The crystalline structure and optical properties of pure tungsten oxide WO3 and Fe-doped WO3 thin films deposited on sapphire substrates were investigated. The X-ray diffraction analysis showed that the thin films exhibited different crystal phases depending on the substrate temperature. The presence of Fe in the deposited layer influenced the film structure and reduced the optical bandgap of the 4% Fe-doped WO3 thin film.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Amit Kumar Singh, Saurabh Yadav, P. K. Kulriya, Y. S. Katharria
Summary: In this study, the annealing effects of sapphire substrate on beta-Ga2O3 thin films were investigated. The results showed that annealing improved the crystalline quality of the thin films and confirmed the presence of Ga-O bonds. The annealing temperature of the sapphire substrate influenced the film quality and the diffusion of aluminum atoms.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Nisha, Palash Kumar Basu
Summary: This work provides a detailed study on the gasochromic properties of tungsten oxide at different operating conditions, sol and doping concentrations. The hydrogen sensing results are compared with material characterization to gain more insight into the gasochromic performance. The effect of noble metal doping on the gasochromic behavior is also explored, and Pt-doped samples show better response than Pd-doped ones.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Ph Nonglen Meitei, Borish Moirangthem, Chitralekha Ngangbam, Mir Waqas Alam, Naorem Khelchand Singh
Summary: In this study, gadolinium oxide thin films were successfully deposited on a silicon substrate using electron beam evaporation technique, and the films were polycrystalline with a cubic crystal system after annealing at different temperatures. The annealed films showed improved electrical performance and fast switching response, making them suitable for photodetector applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Physics, Multidisciplinary
C. H. Raj Kishor, M. Ruksana, T. Amisha, P. M. Aneesh
Summary: In this study, V2O5/NiO heterojunction device was fabricated using both physical and chemical deposition techniques. The structural, optical and morphological properties of the V2O5 and NiO thin films were investigated. The electrical properties of the heterojunction were studied, revealing a rectifying nature with a rectification ratio of 12, a bias voltage of 0.7 V, and a knee voltage of 0.58 V. The built-in potential of the device was determined to be 0.54 V from the C-V characteristics.
Article
Materials Science, Ceramics
Ban K. Mohammed, Mustafa K. A. Mohammed, Duha S. Ahmed
Summary: This paper investigates the structural, optical, and electrical properties of undoped and copper-incorporated nickel oxide films. The Cu-doped NiO films exhibit smooth, hole-free, crack-free, and homogeneous surfaces. These films show high optical transparency and potential application as window layers in solar cells.
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Nisha, Palash Kumar Basu
Summary: A novel method of sodium-ion detection from aqueous solutions based on a change of optical transmittance is proposed. Tungsten oxide-coated indium tin oxide (ITO) samples for selective sodium-ion detection are prepared from varying concentrations of peroxo tungstic oxide precursors using a simple cathodic electrodeposition method. The sensor exhibits good selectivity toward N+ compared to K+ and Ca2+ ions and linear response in the range of 10-150 mM Na+. Simple construction, higher response, and selectivity make it a promising method for sodium sensing in food industries and health monitoring.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Physical
Raoul Blume, Wolfram Calvet, Aliakbar Ghafari, Thomas Mayer, Axel Knop-Gericke, Robert Schloegl
Summary: NiOx films on Si(111) in contact with oxygen at elevated temperatures exhibit the creation and replenishing of oxygen vacancies, resulting in spectral changes and altered electronic levels. The presence of oxygen vacancies leads to changes in bond lengths and charge distribution of surrounding atoms.
Article
Materials Science, Ceramics
Z. M. H. El-Qahtani, Medhat A. El-Hadek, Maged F. Alotaibi, P. Petkov, A. M. Adam
Summary: Thin layers of Bi2-chalcogenides were evaporated on glass substrates using vacuum thermal evaporation, and their properties were enhanced through annealing. The crystal size increased while micro-strain and dislocation density decreased. Annealing also resulted in notable changes in optical band gap and transmittance.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Electrical & Electronic
Sukru Cavdar, Yasemin Sahin, Neslihan Turan, Haluk Koralay, Nihat Tugluoglu
Summary: In this study, undoped and Cd-doped ZnO thin films were prepared using the SILAR technique and their structural and electrical properties were analyzed. The results showed that the thin films had a hexagonal wurtzite structure and the electrical properties varied with the amount of Cd dopant. Additionally, p-n junction diode structures were created to study the light sensitivity and photoresponse characteristics of the films. The findings are important for the design and fabrication of photodiodes in optoelectronic applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Kouame Boko Joel-Igor N'Djore, Moussa Grafoute, Younes Makoudi, Wael Hourani, Christophe Rousselot
Summary: In this study, reactive magnetron sputtering was used to deposit tungsten oxide films on glass and silicon substrates. The Capacitance meter method was proposed to study the electrical properties of resistive WOx films, and a correlation between the deposition process and WOx physico-chemical properties was established. The films were divided into four zones based on the hysteresis of the W-Ar-O-2 system, and the identification of these zones was confirmed by various film properties. The capacitance-voltage curves of the metal-oxide-semiconductor structures showed a gradual evolution with increasing oxygen flow rate, and the ion density and flat band voltage had an inverse relationship with the oxygen flow rate. The Terman method was used to study the WOx-Si interface trap density distribution.
Article
Energy & Fuels
Govindarajan Durai, Parasuraman Kuppusami, Subramanian Arulmani, Sambandam Anandan, Shaik Khadeer Pasha, Soorathep Kheawhom
Summary: Transition metal oxides, particularly Cr-doped CuO, exhibit improved conductivity and enhanced supercapacitive performance, with the Cr-doped CuO thin-film electrode developed at a substrate temperature of 573 K showing the highest areal capacitance of 209 mF cm(-2) and excellent cycling stability in 1 M KOH.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Chemistry, Physical
Ranveer Singh, R. Sivakumar, S. K. Srivastava, Tapobrata Som
APPLIED SURFACE SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
T. Dhandayuthapani, R. Sivakumar, R. Ilangovan, C. Sanjeeviraja, K. Jeyadheepan, C. Gopalakrishnan, P. Sivaprakash, S. Arumugam
Article
Engineering, Electrical & Electronic
S. Ponmudi, R. Sivakumar, C. Sanjeeviraja, C. Gopalakrishnan, T. Okamoto
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2020)
Article
Engineering, Electrical & Electronic
T. Dhandayuthapani, R. Sivakumar, D. Zheng, H. Xu, R. Ilangovan, C. Sanjeeviraja, J. Lin
Summary: This study presents a two-step process for the low-temperature preparation of WO3/TiO2 films, where the deposition of WO3 nanoplates on the TiO2 layer effectively improves the current density of the TiO2 films. The electrochemical performance of the annealed WO3/TiO2 films exhibited high coloration efficiency, good optical modulation, rapid response time, and excellent durability for 1000 cycles, attributed to the interconnected nanoplate bundles and complementarity between the WO3-TiO2 layers.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
R. Vignesh, R. Sivakumar, C. Sanjeeviraja
Summary: This study investigates the impact of precursor solution concentration on the optical parameters of nebulized spray deposited spinel structured hausmannite manganese oxide thin films. Various optical characteristics, including X-ray diffraction, Raman spectra, photoluminescence emission, and optical transmittance were analyzed. Results showed that the films exhibit specific optical properties and structural features, with transmittance decreasing as solution concentration increases.
Article
Materials Science, Ceramics
G. Geetha, R. Sivakumar, C. Sanjeeviraja, V Ganesh
Summary: In this study, zinc tungstate (ZnWO4) nanoparticles were successfully synthesized using a co-precipitation technique without the addition of templates or complexing agents. It was found that annealing temperatures significantly affect the crystallization and crystallite size of the nanoparticles, with well dispersed spherical solid shells and nanoplatelet morphology observed. The decrease in optical energy band gap value of ZnWO4 was attributed to the increase in crystallite size, which in turn affected its luminescence properties.
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
R. Vignesh, V. P. Brintha Mathy, G. Geetha, R. Sivakumar, C. Sanjeeviraja
Summary: The study reports on the thermochromism of m-BiVO4 films prepared by a modified citrate route of simple sol-gel spin coating method, showing a clear thermochromic behavior of the films, possibly related to structural changes.
Article
Optics
M. Girish, R. Sivakumar, C. Sanjeeviraja
Summary: This study focuses on the different properties of Cd1-xMnxS thin films deposited on glass substrates using a nebulized spray technique at 300 and 400 °C. The structural, compositional, surface morphology, optical, and magnetic properties of the films were investigated. The results show that the structure and optical properties of the films are influenced by Mn concentration and substrate temperature, while the magnetic properties are affected by the interaction between dopant and host lattice electrons.
Article
Optics
S. R. Cynthia, R. Sivakumar, C. Sanjeeviraja
Summary: The ternary CuO:SnO2:ZnO (1:1:1) thin films prepared by radio frequency magnetron sputtering technique showed good sensing characteristics towards NH3 gas detection, with excellent crystalline nature and surface morphology variation. The films exhibited a highest optical transmittance of 87% in the visible region, and excellent sensitivity and stability towards NH3 gas detection at room temperature.
Article
Materials Science, Multidisciplinary
Arul Carolin Amala, Ravi Vignesh, Gobalakrishnan Vasanthi Geetha, Rengasamy Sivakumar
Summary: High electrochromic coloration efficiency vanadium oxide thin films were synthesized using a simple sol-gel spin coating technique. Structural studies confirmed the formation of mixed phase and pure beta-V2O5 phase at different temperatures. The films exhibited improved optical properties at higher temperatures, while the electrochromic behavior was detected in a specific electrolyte solution.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Ranveer Singh, Rengasamy Sivakumar, Sanjeev Kumar Srivastava, Tapobrata Som
Summary: This study reveals the influence of MoOx film thickness on the hole-blocking property of heterojunctions and the unique characteristics of the film in preventing hole flow. Experimental results show that a 10 nm-thick MoOx film exhibits the best hole-blocking property, with subsequent treatments affecting its performance to some extent.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Inorganic & Nuclear
G. Geetha, S. P. Keerthana, K. Madhuri, R. Sivakumar
Summary: The study investigated the photocatalytic degradation performance of zinc tungstate nanoparticles prepared using different volumes of solvent, with the most efficient dye removal observed at a 30 ml solvent volume. The results showed that ZnWO4 exhibited good crystallinity and optical properties, making it a promising candidate for photocatalytic applications.
INORGANIC CHEMISTRY COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
B. Muni Babu, R. Sivakumar, C. Sanjeeviraja
Summary: In this work, we reported the enhanced photocatalytic behavior of copper tin hydroxide-based catalyst materials for the degradation of methylene blue dye. The catalyst materials were prepared by a simple co-precipitation technique. The study revealed the crystal phase and morphology of the samples, and analyzed the optical properties and emission spectra to understand the improved photocatalytic performance.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
G. V. Geetha, R. Sivakumar, Y. Slimani, Y. Kuroki, C. Sanjeeviraja
Summary: Nowadays, environmental water pollution caused by hazardous heavy metals, especially azo dyes in textile industries, has become a serious concern affecting human health and aquatic life. Photocatalysis using zinc tungstate (ZnWO4) catalysts synthesized through co-precipitation approach with the assistance of surfactants like hexamethyl tetramine (HMTA) and polyvinyl pyrrolidone (PVP) proves to be an efficient method for the removal of water pollution. The degradation of methylene blue (MB) dye by ZnWO4 catalysts shows promising results, achieving complete degradation within 90 minutes, with the highest degradation efficiencies observed for ZnWO4 catalysts containing 0.7 g of HMTA and 0.5 g of PVP surfactants.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Proceedings Paper
Physics, Condensed Matter
G. Geetha, R. Sivakumar, Y. Kuroki, C. Gopalakrishnan, C. Sanjeeviraja
DAE SOLID STATE PHYSICS SYMPOSIUM 2019
(2020)