C. Pelletier

Bio: C. Pelletier is an academic researcher from Institut national des sciences appliquées. The author has contributed to research in topics: Variable-range hopping & Percolation theory. The author has an hindex of 2, co-authored 4 publications receiving 22 citations.

Cadmium Concentration Dependence of Mobility in Cadmium-Doped Lead Telluride

Abstract: Lead telluride doped with cadmium is grown in a two temperature furnace. The cadmium content is controlled through cadmium vapor pressure. Electronic concentration and Hall mobility are measured for cadmium concentrations up to 1.65 × 1021 cm−3 at 77 and 300 K. Mobility variations are fairly explained by a model taking into account dispersion on acoustic and optical phonons, and neutral impurities. On a realise le dopage du Tellurure de Plomb par le Cadmium dans un four a deux temperatures. La concentration en Cadmium a ete ajustee a partir de la pression partielle de Cadmium. La concentration electronique et la mobilite de Hall ont ete mesurees pour des concentrations de Cadmium allant jusqu'a 1,65 × 1021 cm−3. Les variations de mobilite sont correctement interpretees par un modele prenant en compte les dispersions sur les phonons acoustiques et optiques et sur les impuretes neutres.

Electronic conduction in GaAs at low temperatures

Abstract: Experimental results concerning the Hall mobility of n-GaAs samples are compared to calculated values in the low-temperature range. The procedure used takes into account the actual value for the scattering factor rH which up to present had been considered equal to 1. In this temperature range where ionized impurity scattering is predominant, rH can reach values as high as 1.5 for pure samples. As a consequence, by the present analysis more accurate information about the impurity concentration in the samples can be obtained. Des resultats experimentaux concernant la mobilite de Hall d'echantillons de n-GaAs out ete compares aux valeurs calculees aux basses temperatures. La procedure utilisee tient compte de la valeur reelle du facteur de diffusion rH qui a ete consideree egale a 1 jusqu'a present. Dans la gamme de temperature ou la dispersion par les impuretes ionisees est predominante, rH peut atteindre des valeurs depassant 1,5 pour les echantillons les plus purs. En consequence, l'analyse presente nous permet d'obtenir une information plus precise sur les concentrations en impuretes des echantillons.

Méthode itérative de calcul des concentrations en éléments donneurs et accepteurs d'un semiconducteur faiblement dopé : application au cas de GaAs de type n

Abstract: 2014 Up to now, the methods used to obtain the concentrations of impurities in a semiconductor disregard the actual value of the dispersion factor rH which has been taken constant and equal to 1. However, this dispersion factor is not a constant and its values can reach and even exceed 1.5 in some cases. A numerical iterative method is proposed here for n-GaAs that enable both the value of the dispersion factor rH as a function of temperature and impurity concentrations of the sample to be calculated. REVUE DE PHYSIQUE APPLIQUÉE TOME 12, MAI 1977, PAGE Classification Physics Abstracts 8.220 8.224 8.272

Electronic Properties of a Semiconductor Superlattice II. Low Temperature Mobility Perpendicular to the Superlattice

Abstract: Low temperature mobilities parallel to the layers of a heavily doped n-type GaAs–Ga 1- x Al x As superlattice are calculated as a function of carrier concentrations. Assumed scattering mechanisms are Coulomb scattering from donor ions and surface roughness scattering at the interface. The subband structure in the presence of the band bending is calculated by the variational method. The surface roughness scattering is shown to be relatively unimportant and the Coulomb scattering is dominant. The mobility in the modulation doping case becomes nearly one order of magnitude larger than that in the uniform doping case in agreement with recent experiments. The band bending effect is important in the modulation doping case and reduce the mobility at large carrier concentrations. The intersubband scattering greatly reduces the mobility when electrons occupy higher subbands.

Transition temperature from band to hopping direct current conduction in crystalline semiconductors with hydrogen-like impurities: Heat versus Coulomb attraction

Abstract: For nondegenerate bulk semiconductors, we have used the virial theorem to derive an expression for the temperature Tj of the transition from the regime of “free” motion of electrons in the c-band (or holes in the υ-band) to their hopping motion between donors (or acceptors). Distribution of impurities over the crystal was assumed to be of the Poisson type, while distribution of their energy levels was assumed to be of the Gaussian type. Our conception of the virial theorem implementation is that the transition from the band-like conduction to hopping conduction occurs when the average kinetic energy of an electron in the c-band (hole in the υ-band) is equal to the half of the absolute value of the average energy of the Coulomb interaction of an electron (hole) with the nearest neighbor ionized donor (acceptor). Calculations of Tj according to our model agree with experimental data for crystals of Ge, Si, diamond, etc. up to the concentrations of a hydrogen-like impurity, at which the phase insulator-metal...

Electrical properties of low-temperature GaAs grown by molecular beam epitaxy and migration enhanced epitaxy

Abstract: Measurements on low-temperature GaAs epitaxial layers (LT-GaAs) grown by molecular beam epitaxy and migration enhanced epitaxy showed that the excess arsenic incorporated during growth played a crucial role in determining their electrical properties. The electrical transport in LT-GaAs grown by a standard molecular beam epitaxy proceeded mainly via a hopping process, which showed a higher activation energy and onset temperature than those usually observed in lightly doped semiconductors. Using migration enhanced epitaxy to grow LT-GaAs, we were able to substantially reduce the density of As-rich defects and to achieve a good Hall mobility in Be-doped LT-GaAs. The study presented here indicates that, with controlled excess arsenic incorporation during growth, LT-GaAs can vary in a range of conduction properties and thus can be engineered for different device applications.