Browsing by Author "Mandelis, Andreas"
Now showing items 1-20 of 42
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Absolute nonradiative energy-conversion-efficiency spectra in Ti3+:Al2O3 crystals measured by noncontact quadrature photopyroelectric spectroscopy
Mandelis, Andreas; Vanniasinkam, J.; Budhudu, S.; Othonos, Andreas S.; Kokta, M. (1993)Photopyroelectric spectroscopy (PPES) was used in a noncontact experimental configuration to obtain high-resolution absolute spectra of the optical-to-thermal energy-conversion efficiency (nonradiative coefficient), ηNR(λ), ...
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Diagnostics of nonradiative defects in the bulk and surface of brewster-cut Ti:sapphire laser materials using photothermal radiometry
Vanniasinkam, J.; Munidasa, M.; Othonos, Andreas S.; Kokta, M.; Mandelis, Andreas (1997)The understanding of the problem of nonradiative energy conversion in solid-state laser materials is a key factor in improving the overall efficiency of solid-state lasers. Furthermore, the reduction of the heat generated ...
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High-resolution quadrature photopyroelectric spectroscopy of a-Si:H thin films deposited on silicon wafers
Shen, Jun; Mandelis, Andreas; Othonos, Andreas S.; Vanniasinkam, Joseph (1995)The recently developed photothermal technique of quadrature photopyroelectric spectroscopy (Q-PPES) has been applied to measurements of amorphous Si thin films deposited on crystalline Si substrates. Direct, meaningful ...
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Infrared Real-Time-Normalized Photopyroelectric Measurements of Crystalline Germanium - Instrumentation and Spectroscopy
Christofides, Constantinos; Mandelis, Andreas; GHANDI, K.; WAGNER, RE (1990)
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Laser photothermal diagnostics of genuine and counterfeit British and United States banknotes
Othonos, Andreas S.; Mandelis, Andreas; Nestoros, Marios; Christofides, Constantinos (1997)Laser-induced, frequency-scanned IR photothermal radiometry was used to investigate the thermophysical properties of the paper on which several genuine and counterfeit British (pound 10) and U.S. ($50, $100) currency bills ...
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Laser-induced photothermal reflectance investigation of silicon damaged by arsenic ion implantation: A temperature study
Vitkin, I. A.; Christofides, Constantinos; Mandelis, Andreas (1989)Laser-induced photothermal reflectance (PTR) measurements of arsenic-implanted silicon are reported. The photothermal signals as a function of temperature are presented for both annealed and as-implanted silicon films. The ...
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Non-contacting measurements of photocarrier lifetimes in bulk- and polycrystalline thin-film Si photoconductive devices by photothermal radiometry
Mandelis, Andreas; Othonos, Andreas S.; Christofides, Constantinos; Bousseysaid, J. (1996)Laser-induced and frequency-scanned infrared photothermal radiometry was applied to a crystalline-Si photoconductive device, and to polysilicon thin-film photoconductors deposited on oxidized Si substrates by an LPCVD ...
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Noncontact carrier lifetime depth profiling of ion-implanted Si using photothermal radiometry
Othonos, Andreas S.; Salnick, Alex; Mandelis, Andreas; Christofides, Constantinos (1997)
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Noncontact Lifetime Reconstruction in Continuously Inhomogeneous Semiconductors: Generalized Theory and Experimental Photothermal Results for Ion-Implanted Si
Salnick, Alex; Mandelis, Andreas; Othonos, Andreas S.; Christofides, Constantinos (1997)Abstract The common feature of all previous photothermal studies of semiconductors is that only electronically homogeneous materials have been assumed. Correspondingly, both carrier lifetime (τ) and diffusivity (D n) values ...
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Operating Characteristics and Comparison of Photopyroelectric and Piezoelectric Sensors for Trace Hydrogen Gas-Detection .1. Development of a New Photopyroelectric Sensor
Christofides, Constantinos; Mandelis, Andreas (1989)
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Operating Characteristics and Comparison of Photopyroelectric and Piezoelectric Sensors for Trace Hydrogen Gas-Detection .2. Piezoelectric Quartz-Crystal Microbalance Sensor
Christofides, Constantinos; Mandelis, Andreas (1989)
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Optical-Absorption Coefficient and Nonradiative Quantum Efficiency Photopyroelectric Spectra of Pure Crystal Silicon from a Single Modulation Frequency
Christofides, Constantinos; ENGEL, A.; Mandelis, Andreas (1991)
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Optimization and Characterization of a Differential Photopyroelectric Spectrometer
Christofides, Constantinos; GHANDI, K.; Mandelis, Andreas (1990)
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Optimization of the Photopyroelectric Hydrogen Gas Sensor - Geometry and Temperature-Measurements
Christofides, Constantinos; Mandelis, Andreas; ENRIGHT, J. (1991)A new study towards the optimization of a new photopyroelectric hydrogen detector is performed. It has been found that the thickness of the palladium layer evaporated on the active polyvinylidene fluoride (PVDF) film plays ...
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Article
Out-of-Phase Photopyroelectric (PPE) Spectroscopy on Amorphous Semiconductors
Christofides, Constantinos; Mandelis, Andreas (1992)Abstract A PPE spectrometer with self normalization capability has been used for both conventional transmission and thermal wave spectroscopic measurements of amorphous Si thin films, deposited on c—Si substrates. ...
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Out-of-Phase Photopyroelectric (PPE) Spectroscopy on Amorphous Semiconductors
Christofides, Constantinos; Mandelis, Andreas (2013)
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Photopyroelectric (P2e) Sensor for Trace Hydrogen Gas-Detection
Mandelis, Andreas; Christofides, Constantinos (1990)
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Photopyroelectric Detection of Hydrogen Oxygen Mixtures
Christofides, Constantinos; Mandelis, Andreas; RAWSKI, J.; REHM, S. (1993)It has been found that the photopyroelectric (PPE) sensor made of thin-film polyvinylidene fluoride, sputter coated with palladium, can detect trace hydrogen gas in the presence of pure oxygen without significant drift and ...
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Photopyroelectric Detection of Hydrogen Oxygen Mixtures
Christofides, Constantinos; Mandelis, Andreas (1994)It has been found that the photopyroelectric (PPE) sensor made of thin film polyvinylidene fluoride (PVDF), sputter-coated with palladium, can detect trace hydrogen gas in the presence of pure oxygen without significant ...
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Photopyroelectric measurement of the thermal diffusivity of recrystallized high purity aluminum
Peralta, S. B.; Ellis, S. C.; Christofides, Constantinos; Mandelis, Andreas; Sang, H.; Farahbakhsh, B. (1991)Thermal diffusivity measurements on high purity (99.99% pure) aluminum samples are reported, using chirped and sinusoidally-modulated laser excitation and photopyroelectric detection of the thermal wave response. The results ...