A note on Kuttler-Sigillito's inequalities

We provide several inequalities between eigenvalues of some classical eigenvalue problems on domains with $C^2$ boundary in complete Riemannian manifolds. A key tool in the proof is the generalized Rellich identity on a Riemannian manifold. Our results in particular extend some inequalities due to Kutller and Sigillito from subsets of $\mathbb{R}^2$ to the manifold setting

Escobar constants of planar domains

We initiate the study of the higher-order Escobar constants $I_k(M)$, $k\geq 3$, on bounded planar domains $M$. The Escobar constants $I_k$ of the unit disk and a family of polygons are provided

Influence des collisions nucléaires sur la linéarite des détecteurs à semiconducteurs

On a déterminé le défaut de hauteur d'impulsion dans les diodes à barrière de surface bombardées par des ions He+, N+ et Ne + d'énergies comprises entre 30 et 150 keV. L'influence des collisions nucléaires et de la canalisation des ions est plus spécialement analysée

Spectromètres Ge(Li) 0 absorption totale

On a réalisé divers spectromètres Ge(Li) à absorption totale constitués par deux diodes fonctionnant en coïncidence-somme, ainsi qu'un détecteur puits de 52 cm3

ANALYSIS AND ORIGIN OF POINT DEFECTS IN SILICON AFTER LIQUID PHASE TRANSIENT ANNEALING

Works devoted to the study of point defects in pulsed laser annealed silicon are reviewed by means of electrical characterization. Tailing effects of the implanted distribution are responsible for the observed residual defects in the case of a layer amorphized by ion implantation. However, difficulty in annealing some kinds of point defects by reducing the duration of laser pulse have been shown using slightly disordered silicon. Finally, in the case of irradiated virgin silicon, a high level of point defects are created, which are essentially donor levels that introduce a compensating effect in P-type silicon

Compensation in undoped and halogen doped CdTe crystals

A theoretical model is proposed which allows the calculation of the concentration of defects in pure and halogen compensated cadmium telluride grown by the THM method. All associations and ionization reactions are described in terms of the law of mass action. The ionization energies of the defects are taken from the energy level diagram established by taking into account the latest experimental data. The concentrations of the different defects calculated for chlorine doped material are in good agreement with that measured using a time of flight method

Electron spin and cyclotron resonance of laser annealed silicon

EPR and cyclotron resonance investigations have been performed on laser annealed Si wafers, leading to the identification of the [V + O i]- complex in virgin Si and to a donor signal quenching in P-implanted Si

Hydrogen ion passivation of multicrystalline silicon solar cells

It has been recognized that hydrogen can be chosen to passivate the defects present in polycrystalline materials. Technically, the best approach is to use hydrogen ion implantation at low energy (0.5 to 5 keV) by means of a Kaufman or similar type ion source in order to reduce the processing time. For our multiple beam ion source, we have determined the effective concentration profile of the introduced hydrogen, the modification of the optical properties of the implanted wafers and the conditions under which two multicrystalline materials (POLYX and SILSO) will give the greatest improvement in solar cell performance