Modified permittivity observed in bulk Gallium Arsenide and Gallium Phosphide samples at 50 K using the Whispering Gallery mode method

Whispering Gallery modes in bulk cylindrical Gallium Arsenide and Gallium Phosphide samples have been examined both in darkness and under white light at 50 K. In both samples we observed change in permittivity under light and dark conditions. This results from a change in the polarization state of the semiconductor, which is consistent with a free electron-hole creation/recombination process. The permittivity of the semiconductor is modified by free photocarriers in the surface layers of the sample which is the region sampled by Whispering Gallery modes.Comment: 8 pages, 3 figure

Use of whispering-gallery modes and quasi TE0np modes for broadband characterization of bulk gallium arsenide and gallium phosphide samples

The complex permittivity of bulk crystals of semiinsulating gallium arsenide (GaAs) and gallium phosphide (GaP) were measured over the frequency range from 4 to 30 GHz and at temperatures from 30 up to 300 K employing whispering-gallery-mode (WGM) and quasi-TE0 np-mode dielectric-resonator techniques. At temperatures about 40 K, dielectric loss tangent values were below 10 -6 for GaAs and below 10 -5 for GaP. The use of several WGMs, as well as TE0 np modes excited in the same test sample enabled a broad frequency range of measurements (one decade). The real part of the permittivity of GaP and GaAs proved to be frequency independent at microwave frequencies. The dielectric loss tangents of GaAs and GaP increase with temperature and frequency.Jerzy Krupka, David Mouneyrac, John G. Hartnett, and Michael E. Toba

Detrapping and retrapping of free carriers in nominally pure single crystal GaP, GaAs, and 4H-SiC semiconductors under light illumination at cryogenic temperatures

Abstract not availableDavid Mouneyrac, John G. Hartnett, Jean-Michel Le Floch, Michael E. Tobar, Dominique Cros, and Jerzy Krupk

Microwave properties of semi-insulating silicon carbide between 10 and 40 GHz and at cryogenic temperatures

Abstract not availableJohn G. Hartnett, David Mouneyrac, Jerzy Krupka, Jean-Michel le Floch, Michael E. Tobar and Dominique Cro

Electromagnetic properties of polycrystalline diamond from 35 K to room temperature and microwave to terahertz frequencies

Abstract not availableJean-Michel Le Floch, Romain Bara, John G. Hartnett, Michael E. Tobar, David Mouneyrac, Damien Passerieux, Dominique Cros, Jerzy Krupka, Philippe Goy and Sylvain Caroope

Observation of persistent photoconductivity in bulk gallium arsenide and gallium phosphide samples at cryogenic temperatures using the whispering gallery mode method

Abstract not availableJohn G. Hartnett, David Mouneyrac, Jean-Michel Le Floch, Jerzy Krupka, Michael E. Tobar, and D. Cro

Structural and physical–chemical behavior of a CeO₂ nanoparticle based diesel additive during combustion and environmental release

International audienc