Sukumar Basu | Indian institute of technology (original) (raw)
Papers by Sukumar Basu
Sensors & Transducers, 2009
Porous silicon (PS) was fabricated by anodization of p-type crystalline silicon of resistivity 2-... more Porous silicon (PS) was fabricated by anodization of p-type crystalline silicon of resistivity 2-5 Ω cm. After formation, the PS surface was modified by the solution containing noble metal like Pd. Pd-Ag catalytic contact electrodes were deposited on porous silicon and on p-Silicon to fabricate Pd-Ag/PS/p-Si/Pd-Ag sensor structure to carry out the hydrogen sensing experiments. The Sensor was exposed to 1% hydrogen in nitrogen as carrier gas at room temperature (270C). Pd modified sensor showed minimum fluctuations and consistent performance with 86% response, response time and recovery time of 24 sec and 264 sec respectively. The stability experiments were studied for both unmodified and Pd modified sensor structures for a period of about 24 hours and the modified sensors showed excellent durability with no drift in response behavior.
Chemistry and Applications, 2015
Nano-porous titanium dioxide (TiO2) thin films were developed by UV assisted potentiostatic anodi... more Nano-porous titanium dioxide (TiO2) thin films were developed by UV assisted potentiostatic anodization of 99.7% pure titanium foil. The internationally popular soft drink 'Coca-Cola' was used as the electrolyte in this anodization process. Electrochemical oxidation and photoetching were carried out at room temperature and at 10 V potentiostatic bias without and with 400 W UV light illumination respectively. The prepared TiO2 thin film was annealed at 150ᴼC for 3 hours. The surface of the prepared TiO2 film was characterized with Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) to confirm the crystallinity, porous structure and surface roughness. The Optical study revealed a band gap of 3.898 eV. Hot probe method exhibited n-type conductivity of the electrochemically grown TiO2 thin films. Palladium-Silver alloy (Pd-Ag) contacts were deposited laterally on the oxide surface as catalytic metal electrodes to fabricate a planar sensor configuration. The hydrogen sensor study was carried out at different temperatures (100 to 200ᴼC) and in different hydrogen gas concentrations (1000 to 10000 ppm). Nanocrystalline and nano-porous TiO2 sensor was promising to sense hydrogen in air ambient with relatively fast response and recovery times (e.g. ~2.9 s and ~75 s) at the optimum temperature of 150 0 C. Brief mechanism behind the sensing performance has been also discussed.
Sensors and Actuators B: Chemical, 2011
A silicon carbide based field effect transistor (SiC-FET) structure was used for methanol sensing... more A silicon carbide based field effect transistor (SiC-FET) structure was used for methanol sensing. Due to the chemical stability and wide band gap of SiC, these sensors are suitable for applications over a wide temperature range. Two different catalytic metals, Pt and Ir, were tested as gate contacts for detection of methanol. The sensing properties of both Ir gate and Pt gate SiC-FET sensors were investigated in the concentration range 0.3 -5% of methanol in air and in the temperature range 150-350ºC. It was observed that compared to the Ir gate sensor, the Pt gate sensor showed higher sensitivity, faster response and recovery to methanol vapour at comparatively lower temperature, with an optimum around 200ºC. Quantum-chemical calculations were used to investigate the MeOH adsorption and to rationalize the observed non-Langmuir behavior of the response functions. The methanol sensing mechanism of the SiC-FET is discussed.
Public Administration, 1953
Oxidation of Metals, 1987
Two methods are presented for the analysis of oxygen tracer isotope "double oxidation" experiment... more Two methods are presented for the analysis of oxygen tracer isotope "double oxidation" experiments. Mass balance criteria are presented for inferring oxide growth mechanisms from the oxygen isotope profile. For the case of inward growing scales, a diffusion model is presented which describes the tracer distribution as a function of lattice and grain boundary diffusivities, grain size and the parabolic growth rate.
Journal of Colloid and Interface Science, 1982
Oxidation of Metals, 1991
Austenitic 0.6, and 1.5wt.% Si were produced both by conventional and rapid solidification proces... more Austenitic 0.6, and 1.5wt.% Si were produced both by conventional and rapid solidification processing. The cyclic oxidation resistance of these alloys was studied at 900~ in a S0:-02 gas mixture to elucidate the role of alloy microstructure and Si content on oxidation properties in bioxidant atmospheres. All the large-grained, conventionally processed alloys exhibited breakaway oxidation during cyclic oxidation due to their poor rehealing characteristics. The rapidly solidified, fine-grained alloys that contained less than 1.5 wt.% Si exhibited very protective oxidation behavior. There was considerable evidence of sulfur penetration through the protective chromia scale. The rapidly solidified alloys that contained 1.5 wt. % Si underwent repeated scale spallation that led to breakaway oxidation behavior. The scale spallation was attributed to the Jbrmation of an extensive silica sublayer in the presence of sulfur in the atmosphere.
Journal of Applied Physics, 2013
Central European Journal of Chemistry, 2013
ABSTRACT
Advanced Science Letters, 2014
ABSTRACT
Materials Letters, 1982
ABSTRACT Lead-tin telluride was prepared as a polycrystalline powder by heating a mixture of the ... more ABSTRACT Lead-tin telluride was prepared as a polycrystalline powder by heating a mixture of the component elements in a lead iodide flux at about 650°C. The powder, as prepared, can be used as raw material for single crystal growth or epitaxial film preparation.
A thin layer (∼1 m) of sol–gel grown nanocrystalline p-type TiO2 was deposited on a thermally oxi... more A thin layer (∼1 m) of sol–gel grown nanocrystalline p-type TiO2 was deposited on a thermally oxidized
p-Si (2–5 cm resistivity and (1 0 0) orientation) substrate. The surface was characterized by X-ray
diffraction (XRD) and field emission scanning electron microscopy (FESEM), which also confirmed the
nanocrystallinity of the material. Optical absorption spectroscopy was carried out to calculate the band
gap ofthe material. Two lateral Pd contacts were used as the catalytic metal electrodes on TiO2 to fabricate
the resistive gas sensor for hydrogen sensing. Detail gas response characteristics, selectivity and the stability
of the sensor structure were studied. The sensors showed high response (∼55%) to hydrogen with
an appreciable short response time of 2 s at the optimized temperature, 175 ◦C and biasing voltage, 0.1V
in a steady dynamic atmosphere of 1% H2 with N2 as carrier gas. For practical applications, similar set of
sensor experiments was also performed in air ambient. At 100 ◦C and 1.0V bias the response magnitude
was reduced to 49% but the response time came down to 1.3 s. The recovery time was lowest (∼34 s) at
150 ◦C. The reduction in the recovery time in air is possibly due to quick removal of residual hydrogen
from the surface ofthe sensor by interaction with oxygen presentin air. The sensors showed selectivity to
hydrogen and good stability. There was no degradation after working for 42 h in a discrete mode (6 h/day)
in nitrogen and also in air. A possible gas sensing mechanism was suggested with a qualitative energy
band diagram.
Sensors & Transducers, 2009
Porous silicon (PS) was fabricated by anodization of p-type crystalline silicon of resistivity 2-... more Porous silicon (PS) was fabricated by anodization of p-type crystalline silicon of resistivity 2-5 Ω cm. After formation, the PS surface was modified by the solution containing noble metal like Pd. Pd-Ag catalytic contact electrodes were deposited on porous silicon and on p-Silicon to fabricate Pd-Ag/PS/p-Si/Pd-Ag sensor structure to carry out the hydrogen sensing experiments. The Sensor was exposed to 1% hydrogen in nitrogen as carrier gas at room temperature (270C). Pd modified sensor showed minimum fluctuations and consistent performance with 86% response, response time and recovery time of 24 sec and 264 sec respectively. The stability experiments were studied for both unmodified and Pd modified sensor structures for a period of about 24 hours and the modified sensors showed excellent durability with no drift in response behavior.
Chemistry and Applications, 2015
Nano-porous titanium dioxide (TiO2) thin films were developed by UV assisted potentiostatic anodi... more Nano-porous titanium dioxide (TiO2) thin films were developed by UV assisted potentiostatic anodization of 99.7% pure titanium foil. The internationally popular soft drink 'Coca-Cola' was used as the electrolyte in this anodization process. Electrochemical oxidation and photoetching were carried out at room temperature and at 10 V potentiostatic bias without and with 400 W UV light illumination respectively. The prepared TiO2 thin film was annealed at 150ᴼC for 3 hours. The surface of the prepared TiO2 film was characterized with Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) to confirm the crystallinity, porous structure and surface roughness. The Optical study revealed a band gap of 3.898 eV. Hot probe method exhibited n-type conductivity of the electrochemically grown TiO2 thin films. Palladium-Silver alloy (Pd-Ag) contacts were deposited laterally on the oxide surface as catalytic metal electrodes to fabricate a planar sensor configuration. The hydrogen sensor study was carried out at different temperatures (100 to 200ᴼC) and in different hydrogen gas concentrations (1000 to 10000 ppm). Nanocrystalline and nano-porous TiO2 sensor was promising to sense hydrogen in air ambient with relatively fast response and recovery times (e.g. ~2.9 s and ~75 s) at the optimum temperature of 150 0 C. Brief mechanism behind the sensing performance has been also discussed.
Sensors and Actuators B: Chemical, 2011
A silicon carbide based field effect transistor (SiC-FET) structure was used for methanol sensing... more A silicon carbide based field effect transistor (SiC-FET) structure was used for methanol sensing. Due to the chemical stability and wide band gap of SiC, these sensors are suitable for applications over a wide temperature range. Two different catalytic metals, Pt and Ir, were tested as gate contacts for detection of methanol. The sensing properties of both Ir gate and Pt gate SiC-FET sensors were investigated in the concentration range 0.3 -5% of methanol in air and in the temperature range 150-350ºC. It was observed that compared to the Ir gate sensor, the Pt gate sensor showed higher sensitivity, faster response and recovery to methanol vapour at comparatively lower temperature, with an optimum around 200ºC. Quantum-chemical calculations were used to investigate the MeOH adsorption and to rationalize the observed non-Langmuir behavior of the response functions. The methanol sensing mechanism of the SiC-FET is discussed.
Public Administration, 1953
Oxidation of Metals, 1987
Two methods are presented for the analysis of oxygen tracer isotope "double oxidation" experiment... more Two methods are presented for the analysis of oxygen tracer isotope "double oxidation" experiments. Mass balance criteria are presented for inferring oxide growth mechanisms from the oxygen isotope profile. For the case of inward growing scales, a diffusion model is presented which describes the tracer distribution as a function of lattice and grain boundary diffusivities, grain size and the parabolic growth rate.
Journal of Colloid and Interface Science, 1982
Oxidation of Metals, 1991
Austenitic 0.6, and 1.5wt.% Si were produced both by conventional and rapid solidification proces... more Austenitic 0.6, and 1.5wt.% Si were produced both by conventional and rapid solidification processing. The cyclic oxidation resistance of these alloys was studied at 900~ in a S0:-02 gas mixture to elucidate the role of alloy microstructure and Si content on oxidation properties in bioxidant atmospheres. All the large-grained, conventionally processed alloys exhibited breakaway oxidation during cyclic oxidation due to their poor rehealing characteristics. The rapidly solidified, fine-grained alloys that contained less than 1.5 wt.% Si exhibited very protective oxidation behavior. There was considerable evidence of sulfur penetration through the protective chromia scale. The rapidly solidified alloys that contained 1.5 wt. % Si underwent repeated scale spallation that led to breakaway oxidation behavior. The scale spallation was attributed to the Jbrmation of an extensive silica sublayer in the presence of sulfur in the atmosphere.
Journal of Applied Physics, 2013
Central European Journal of Chemistry, 2013
ABSTRACT
Advanced Science Letters, 2014
ABSTRACT
Materials Letters, 1982
ABSTRACT Lead-tin telluride was prepared as a polycrystalline powder by heating a mixture of the ... more ABSTRACT Lead-tin telluride was prepared as a polycrystalline powder by heating a mixture of the component elements in a lead iodide flux at about 650°C. The powder, as prepared, can be used as raw material for single crystal growth or epitaxial film preparation.
A thin layer (∼1 m) of sol–gel grown nanocrystalline p-type TiO2 was deposited on a thermally oxi... more A thin layer (∼1 m) of sol–gel grown nanocrystalline p-type TiO2 was deposited on a thermally oxidized
p-Si (2–5 cm resistivity and (1 0 0) orientation) substrate. The surface was characterized by X-ray
diffraction (XRD) and field emission scanning electron microscopy (FESEM), which also confirmed the
nanocrystallinity of the material. Optical absorption spectroscopy was carried out to calculate the band
gap ofthe material. Two lateral Pd contacts were used as the catalytic metal electrodes on TiO2 to fabricate
the resistive gas sensor for hydrogen sensing. Detail gas response characteristics, selectivity and the stability
of the sensor structure were studied. The sensors showed high response (∼55%) to hydrogen with
an appreciable short response time of 2 s at the optimized temperature, 175 ◦C and biasing voltage, 0.1V
in a steady dynamic atmosphere of 1% H2 with N2 as carrier gas. For practical applications, similar set of
sensor experiments was also performed in air ambient. At 100 ◦C and 1.0V bias the response magnitude
was reduced to 49% but the response time came down to 1.3 s. The recovery time was lowest (∼34 s) at
150 ◦C. The reduction in the recovery time in air is possibly due to quick removal of residual hydrogen
from the surface ofthe sensor by interaction with oxygen presentin air. The sensors showed selectivity to
hydrogen and good stability. There was no degradation after working for 42 h in a discrete mode (6 h/day)
in nitrogen and also in air. A possible gas sensing mechanism was suggested with a qualitative energy
band diagram.