Vikram Kumar | Lehigh University (original) (raw)

Papers by Vikram Kumar

Journal of Electronic Materials, 2003

Improved performance of the ohmic contacts on n-GaN has been demonstrated with the use of MoAu as... more Improved performance of the ohmic contacts on n-GaN has been demonstrated with the use of MoAu as the capping layer on TiAl metallization. Contact resistance as low as 0.13 Θ-mm was achieved in these ohmic contacts when annealed at 850C for 30 sec. We have studied the long-term thermal stability of these contacts at 500C, 600C, 750C, and 850C, respectively.

Diam Relat Mater, 1993

Abstract Deposition onto GaAs of dielectric film with good interfacial properties is difficult ow... more Abstract Deposition onto GaAs of dielectric film with good interfacial properties is difficult owing to the high surface state densities at the GaAs surface. Study of diamond-like carbon (DLC)/GaAs heterostructures is worthwhile because of the advantageous properties of ...

IEEE Transactions on Electron Devices, 2000

Abstract—Density and energetic distributions of interface states between metal-semiconductor rect... more Abstract—Density and energetic distributions of interface states between metal-semiconductor rectifying contacts in sub-micron GaAs MESFET and AlGaAs/InGaAs pseudomorphic high elec-tron mobility transistors (HEMT's) have been studied. Electrical properties of the ...

Colloid and Polymer Science, 2010

Page 1. ORIGINAL CONTRIBUTION Role of surface modification of colloidal CdSe quantum dots on the ... more Page 1. ORIGINAL CONTRIBUTION Role of surface modification of colloidal CdSe quantum dots on the properties of hybrid organic–inorganic nanocomposites Umesh Kumar & Kusum Kumari & Shailesh N. Sharma & Mahesh Kumar & VD Vankar & Rita Kakkar & Vikram Kumar ...

Spie Proceedings Series, 2002

Journal of Physics D Applied Physics, Feb 8, 2009

... Pankaj Kumar1,2,3, SC Jain1, Vikram Kumar1, Suresh Chand1 and RP Tandon2 1 Centre for Organic... more ... Pankaj Kumar1,2,3, SC Jain1, Vikram Kumar1, Suresh Chand1 and RP Tandon2 1 Centre for Organic Electronics, National Physical Laboratory, Dr KS Krishnan Road, New Delhi-110012, India 2 Department of Physics and Astrophysics, University of Delhi, Delhi ... P Kumar et al ...

Phys Rev B, 1992

Photo-deep-level transient spectroscopy detection of a new level with thermal activation energy 0... more Photo-deep-level transient spectroscopy detection of a new level with thermal activation energy 0.22 eV of DX centers in silicon doped Al x Ga 1-x As (x equals 0.26) is reported for the first time. The observation of this level directly proves the negative-U properties of DX centers ...

Phys Rev Lett, 1987

... Our experiment with only a P-doped polysilicon layer gives a similar result. Suman B. Iyer an... more ... Our experiment with only a P-doped polysilicon layer gives a similar result. Suman B. Iyer andVikram Kumar Department of Physics Indian Institute of Science Bangalore, 560012 India ... Rev. Lett. 59, 2116 (1987)]. E. M. Sankarnarayan, S. Annamalai, G. Vishwanath, SB ...

J Appl Phys, 1988

TABLE Í. Comparative iist of reported resuits. E ro (eV) (S" &am... more TABLE Í. Comparative iist of reported resuits. E ro (eV) (S" ') Method Material Ref. 0.34 8 ХЮ" isothermal annealing Conducting 6 0.30 2 X10" Isothermal annealing Conducting 5 0.20 1 X10" Isochronal annealing Conducting S 0.26 2.5ХЮ8 TSPC Semi-insulating This work ...

MRS Proceedings, 1995

The effect of hydrogen plasma treatment on the optical and electrical properties of Gallium Antim... more The effect of hydrogen plasma treatment on the optical and electrical properties of Gallium Antimonide bulk single crystals is presented. Plasma exposure gives rise to a layer of defects on the surface. These defects introduce multiple trap levels in the band gap from which a slow emission of carriers is observed during the capacitance - voltage measurements. On removal of the defect layer by controlled etching, the effects of hydrogen passivation are seen. The results of optical measurements indicate that passivation of shallow acceptors is more efficient than that of the donors and in general the passivation efficiency depends on the doping level. Passivation of deep levels and extended defects like grain boundaries and dislocations has also been observed. The thermal stability of the passivated deep level and extended defects is higher than that of the shallow level.

Physica Status Solidi (a), 1983

Journal of Electronic Materials, 2006

Solar Energy Materials and Solar Cells, 2011

Journal of Electronic Materials, 2003

Improved performance of the ohmic contacts on n-GaN has been demonstrated with the use of MoAu as... more Improved performance of the ohmic contacts on n-GaN has been demonstrated with the use of MoAu as the capping layer on TiAl metallization. Contact resistance as low as 0.13 Θ-mm was achieved in these ohmic contacts when annealed at 850C for 30 sec. We have studied the long-term thermal stability of these contacts at 500C, 600C, 750C, and 850C, respectively.

Diam Relat Mater, 1993

Abstract Deposition onto GaAs of dielectric film with good interfacial properties is difficult ow... more Abstract Deposition onto GaAs of dielectric film with good interfacial properties is difficult owing to the high surface state densities at the GaAs surface. Study of diamond-like carbon (DLC)/GaAs heterostructures is worthwhile because of the advantageous properties of ...

IEEE Transactions on Electron Devices, 2000

Abstract—Density and energetic distributions of interface states between metal-semiconductor rect... more Abstract—Density and energetic distributions of interface states between metal-semiconductor rectifying contacts in sub-micron GaAs MESFET and AlGaAs/InGaAs pseudomorphic high elec-tron mobility transistors (HEMT's) have been studied. Electrical properties of the ...

Colloid and Polymer Science, 2010

Page 1. ORIGINAL CONTRIBUTION Role of surface modification of colloidal CdSe quantum dots on the ... more Page 1. ORIGINAL CONTRIBUTION Role of surface modification of colloidal CdSe quantum dots on the properties of hybrid organic–inorganic nanocomposites Umesh Kumar & Kusum Kumari & Shailesh N. Sharma & Mahesh Kumar & VD Vankar & Rita Kakkar & Vikram Kumar ...

Spie Proceedings Series, 2002

Journal of Physics D Applied Physics, Feb 8, 2009

... Pankaj Kumar1,2,3, SC Jain1, Vikram Kumar1, Suresh Chand1 and RP Tandon2 1 Centre for Organic... more ... Pankaj Kumar1,2,3, SC Jain1, Vikram Kumar1, Suresh Chand1 and RP Tandon2 1 Centre for Organic Electronics, National Physical Laboratory, Dr KS Krishnan Road, New Delhi-110012, India 2 Department of Physics and Astrophysics, University of Delhi, Delhi ... P Kumar et al ...

Phys Rev B, 1992

Photo-deep-level transient spectroscopy detection of a new level with thermal activation energy 0... more Photo-deep-level transient spectroscopy detection of a new level with thermal activation energy 0.22 eV of DX centers in silicon doped Al x Ga 1-x As (x equals 0.26) is reported for the first time. The observation of this level directly proves the negative-U properties of DX centers ...

Phys Rev Lett, 1987

... Our experiment with only a P-doped polysilicon layer gives a similar result. Suman B. Iyer an... more ... Our experiment with only a P-doped polysilicon layer gives a similar result. Suman B. Iyer andVikram Kumar Department of Physics Indian Institute of Science Bangalore, 560012 India ... Rev. Lett. 59, 2116 (1987)]. E. M. Sankarnarayan, S. Annamalai, G. Vishwanath, SB ...

J Appl Phys, 1988

TABLE Í. Comparative iist of reported resuits. E ro (eV) (S" &am... more TABLE Í. Comparative iist of reported resuits. E ro (eV) (S" ') Method Material Ref. 0.34 8 ХЮ" isothermal annealing Conducting 6 0.30 2 X10" Isothermal annealing Conducting 5 0.20 1 X10" Isochronal annealing Conducting S 0.26 2.5ХЮ8 TSPC Semi-insulating This work ...

MRS Proceedings, 1995

The effect of hydrogen plasma treatment on the optical and electrical properties of Gallium Antim... more The effect of hydrogen plasma treatment on the optical and electrical properties of Gallium Antimonide bulk single crystals is presented. Plasma exposure gives rise to a layer of defects on the surface. These defects introduce multiple trap levels in the band gap from which a slow emission of carriers is observed during the capacitance - voltage measurements. On removal of the defect layer by controlled etching, the effects of hydrogen passivation are seen. The results of optical measurements indicate that passivation of shallow acceptors is more efficient than that of the donors and in general the passivation efficiency depends on the doping level. Passivation of deep levels and extended defects like grain boundaries and dislocations has also been observed. The thermal stability of the passivated deep level and extended defects is higher than that of the shallow level.

Physica Status Solidi (a), 1983

Journal of Electronic Materials, 2006

Solar Energy Materials and Solar Cells, 2011