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Papers by Perumal Veeramani
Surface and Interface Analysis, 2010
CdZnTe (CZT) is commonly used as a radiation detector material and the surface properties are imp... more CdZnTe (CZT) is commonly used as a radiation detector material and the surface properties are important as they influence detector performance. The surface chemistry is generally controlled through chemical etching and oxidation processes. In this paper, X‐ray photoelectron spectroscopy (XPS) is employed to investigate changes in the surface composition of single‐crystal Cd0.95Zn0.05Te samples after exposure to bromine in methanol (BM) chemical etching treatments and subsequent oxidation in air or 30% H2O2. BM treatment of CZT is found to result in a graded Te‐rich surface layer which increases in thickness as a function of BM concentration. Room‐temperature air oxidation of 0.2% BM‐treated CZT follows a logarithmic rate law. BM‐treated CZT exposed to 30% H2O2 for 30 s shows a linear increase in the TeO2 oxide thickness with increasing BM concentration up to a BM concentration of 1.5%. Above 2% BM concentration, the Te enrichment in the CZT surface region has reached saturation and ...
Journal of Physics D: Applied Physics, 2006
CdTe crystals grown by the Bridgman technique were irradiated by swift heavy ions (SHIs), 100 MeV... more CdTe crystals grown by the Bridgman technique were irradiated by swift heavy ions (SHIs), 100 MeV Ag7+ ions, with fluences varying from 1011 to 1014 ions cm-2 and the damage is investigated by atomic force microscopy, x-ray diffraction, hall effect measurements and photoluminence. It is found that the behaviour of CdTe crystals under a SHI irradiation induces structural disorder, generation
Journal of Physics D: Applied Physics, 2010
IEEE Transactions on Nuclear Science, 2012
IEEE Transactions on Nuclear Science, 2011
IEEE Transactions on Nuclear Science, 2009
MRS Proceedings, 2009
Real time imaging of the electric field distribution in CZT at low temperature has been carried o... more Real time imaging of the electric field distribution in CZT at low temperature has been carried out using the Pockels electro-optical effect. CZT detectors have been observed to show degraded spectroscopic resolution at low temperature due to so-called ‘polarization’ phenomena. By mounting a CZT device in a custom optical cryostat, we have used Pockels imaging to observe the distortion of the electric field distribution in the temperature range 240K - 300K. At 240K the electric field has a severely non-uniform depth distribution, with a high field region occupying ∼10% of the depth of the device under the cathode electrode and a low field in the remainder of the device. Using an alpha particle source positioned inside the vacuum chamber we have performed simultaneous alpha particle transient current (TCT) measurements. At low temperatures the alpha particle current pulses become significantly shorter, consistent with the reduced electron drift time due to a non-uniform electric fiel...
physica status solidi (a), 2008
Journal of Applied Physics, 2009
Journal of Physics D: …, Jan 1, 2009
Page 1. Study on temperature dependent resistivity of indium-doped cadmium zinc telluride This ar... more Page 1. Study on temperature dependent resistivity of indium-doped cadmium zinc telluride This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 J. Phys. D: Appl. Phys. 42 035105 ...
Japanese Journal of …, Jan 1, 2010
Title: Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space S... more Title: Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space Sublimation Method. Authors: Quanzhong Jiang,; Andy W. Brinkman,;Perumal Veeramani,; Paul. J. Sellin,. Affiliation: AA(Physics ...
… Record (NSS/MIC), …, Jan 1, 2010
Surface and Interface Analysis, 2010
CdZnTe (CZT) is commonly used as a radiation detector material and the surface properties are imp... more CdZnTe (CZT) is commonly used as a radiation detector material and the surface properties are important as they influence detector performance. The surface chemistry is generally controlled through chemical etching and oxidation processes. In this paper, X‐ray photoelectron spectroscopy (XPS) is employed to investigate changes in the surface composition of single‐crystal Cd0.95Zn0.05Te samples after exposure to bromine in methanol (BM) chemical etching treatments and subsequent oxidation in air or 30% H2O2. BM treatment of CZT is found to result in a graded Te‐rich surface layer which increases in thickness as a function of BM concentration. Room‐temperature air oxidation of 0.2% BM‐treated CZT follows a logarithmic rate law. BM‐treated CZT exposed to 30% H2O2 for 30 s shows a linear increase in the TeO2 oxide thickness with increasing BM concentration up to a BM concentration of 1.5%. Above 2% BM concentration, the Te enrichment in the CZT surface region has reached saturation and ...
Journal of Physics D: Applied Physics, 2006
CdTe crystals grown by the Bridgman technique were irradiated by swift heavy ions (SHIs), 100 MeV... more CdTe crystals grown by the Bridgman technique were irradiated by swift heavy ions (SHIs), 100 MeV Ag7+ ions, with fluences varying from 1011 to 1014 ions cm-2 and the damage is investigated by atomic force microscopy, x-ray diffraction, hall effect measurements and photoluminence. It is found that the behaviour of CdTe crystals under a SHI irradiation induces structural disorder, generation
Journal of Physics D: Applied Physics, 2010
IEEE Transactions on Nuclear Science, 2012
IEEE Transactions on Nuclear Science, 2011
IEEE Transactions on Nuclear Science, 2009
MRS Proceedings, 2009
Real time imaging of the electric field distribution in CZT at low temperature has been carried o... more Real time imaging of the electric field distribution in CZT at low temperature has been carried out using the Pockels electro-optical effect. CZT detectors have been observed to show degraded spectroscopic resolution at low temperature due to so-called ‘polarization’ phenomena. By mounting a CZT device in a custom optical cryostat, we have used Pockels imaging to observe the distortion of the electric field distribution in the temperature range 240K - 300K. At 240K the electric field has a severely non-uniform depth distribution, with a high field region occupying ∼10% of the depth of the device under the cathode electrode and a low field in the remainder of the device. Using an alpha particle source positioned inside the vacuum chamber we have performed simultaneous alpha particle transient current (TCT) measurements. At low temperatures the alpha particle current pulses become significantly shorter, consistent with the reduced electron drift time due to a non-uniform electric fiel...
physica status solidi (a), 2008
Journal of Applied Physics, 2009
Journal of Physics D: …, Jan 1, 2009
Page 1. Study on temperature dependent resistivity of indium-doped cadmium zinc telluride This ar... more Page 1. Study on temperature dependent resistivity of indium-doped cadmium zinc telluride This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 J. Phys. D: Appl. Phys. 42 035105 ...
Japanese Journal of …, Jan 1, 2010
Title: Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space S... more Title: Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space Sublimation Method. Authors: Quanzhong Jiang,; Andy W. Brinkman,;Perumal Veeramani,; Paul. J. Sellin,. Affiliation: AA(Physics ...
… Record (NSS/MIC), …, Jan 1, 2010