Charge State Of Hydrogen Research Articles

Electronically Induced Instability of a Hydrogen-Carbon Complex in Silicon and Its Dissociation Mechanism

We studied, by deep-level transient spectroscopy (DLTS), the dissociation mechanism of a hydrogen-carbon (H-C) complex, which has a donor level at E c-0.15 eV and acts as an electron trap in crystalline silicon. On the basis of our results and a previously proposed atomic model of the H-C complex, in which the hydrogen atom resides inside a silicon-carbon bond, we have proposed the following dissociation mechanism. The complex is stable in the positive charge state, and to dissociate it needs a hydrogen jump with an activation energy of 1.3 eV to break the bond with carbon and silicon. The complex becomes neutral by capturing an electron from the conduction band or accepting an electron directly from the valence band under electronic excitation, and is consequently dissociated at an activation energy of 0.5 eV due to the loss of binding. Strong evidence for the existence of the negative charge state of hydrogen in crystalline silicon is also presented.

Stopping power of lithium for hydrogen projectiles

Experimental measurements and a theoretical charge state approach for the stopping power of 20–750 keV hydrogen projectiles in solid lithium are presented. We show that it is necessary to consider the different hydrogen charge states as well as the charge exchange processes contribution to the energy loss to properly fit the major trends of the measured data.

Atomic Hydrogen in GaN

ABSTRACTBased on extensive first-principles total-energy calculations we study the electronic structure, atomic geometry and energetics of atomic hydrogen in cubic GaN. All charge states of hydrogen (H+, H0, H-) are examined. For H- the gallium tetrahedral interstitial site is energetically most stable. All other sites are much higher in energy, indicating a high diffusion barrier for H- in GaN. H+ favors positions on a sphere with a radius of ≈ 1 Å and a nitrogen atom in the center. Among these positions the nitrogen antibonding site is energetically most stable. An unexpectedly large negative-U effect (U = —2.5eV) indicates that H0 is unstable.

The Influence of an In-Situ Electric Field on H+ and He+ Implantation Induced Defects in Silicon

ABSTRACTThe influence of in-situ electronic perturbations on defect generation during 150 keV proton implantation into biased silicon p-n junctions has been investigated. The concentration and spatial distribution of the deep traps were characterized using a modification of the double corelation deep level transient spectroscopy technique (D-DLTS). With the in-situ electric field applied, a decrease in concentration of vacancy-related, as well as H-related, traps was observed. 500 keV He+ implantation was also performed to supplement the above studies and to differentiate any passivation effects due to hydrogen. A model based on the charge states of hydrogen and vacancies was used to explain the observed behaviour.

Charge state of hydrogen in crystalline silicon.

An estimate is given for the relative stabilities of neutral and positive bond-center hydrogen interstitials and of negatively charged hydrogen at the antibonding site as a function of Fermi-level position. We predict the hydrogen-related donor level to be below the intrinsic Fermi level, and the existence of a Fermi-energy region around midgap where the neutral charge state is stable.

The charge state of hydrogen and hydrogen diffusion in InP and InGaAs

Hydrogen diffusion is studied in InP, In 0.53Ga 0.47As and InP-based MIS-capacitors. It is shown that hydrogen diffusivity is much higher in p-type than in n-type material both in InP and InGaAs. It is concluded that hydrogen is a deep donor in these materials.

Properties of hydrogen in crystalline silicon under compression and tension.

Employing first-principles calculations, we have studied the behavior of hydrogen in crystalline silicon under compression and tension. The stable site for hydrogen is found to depend critically on both the pressure and on the hydrogen charge state. In particular, as a function of pressure, hydrogen undergoes a transition from an energy minimum at the tetrahedral interstitial site to one at the bond-center site. This results has implications for the behavior of hydrogen in the stress fields of dislocations, grain boundaries, and crack tips.

Charge States of Hydrogen in p-Type and n-Type Silicon

Charge States of Hydrogen in p-Type and n-Type Silicon

Diffusion and Charge State of Hydrogen in Si

Diffusion and Charge State of Hydrogen in Si

Hydrogen in Crystalline Silicon under Compression and Tension

AbstractThe behavior of hydrogen in crystalline silicon (c-Si) containing regions of compressive or tensile stress is important for understanding the solute’s interaction with dislocations, grain boundaries, and crack tips. A series of first-principles total-energy calculations probing the stable site for hydrogen as a function of its charge state, the Fermi level position, and the crystalline lattice constant has been performed. We find that the stable site for hydrogen depends critically on both pressure and on the hydrogen charge state. Furthermore, hydrogen is predicted to undergo a transition from an interstitial site to the bond-center site as a function of pressure.

Theoretical Description of keV Hydrogen Interaction with Jellium Metal

The shift and broadening of the valence and affinity levels of an atom interacting with a metal surface are calculated at all distances outside the surface using a linearized Fermi–Thomas approximation to calculate the Hamiltonian of the bond electron, and first order perturbation theory. The effective charges on both levels are then calculated for all distances from jellium metal at zero temperature. A semi-classical approach is then used to illustrate the relative importance of the charge state in the bulk, the surface, and near surface regions to the final charge state of hydrogen reflected from gold in the energy region 0.1–8 keV.