A theoretical model has been developed to describe the probability of charge transfer from helium cations to dopant molecules inside helium nanodroplets following electron impact ionization. The location of the initial charge site inside helium nanodroplets subject to electron impact has been investigated and is found to play an important role in understanding the ionization of dopants inside h...

The close-coupling approach to electron-helium single ionization is analyzed and several ways of defining the scattering amplitudes are determined, for both equaland unequal-energy outgoing electrons. Nevertheless, the various definitions all lead to the same cross section. The convergent close-coupling sCCCd method with Laguerre sCCC-Ld and box-based sCCC-Bd target functions is applied to calc...

A semiempirical model of single differential cross sections (SDCS) for ionization of water vapor by fast electrons and bare ions is presented. At low secondary-electron energy, the model is based on an asymptotic expansion of the first Born approximation with coefficients, that are independent of projectile properties, evaluated from experimental photoabsorption and protonimpact ionization data...

A B ST R A C T : We studied electron impact ionization of tetramethylsilane (TMS), Si(CH3)4, which is utilized in plasma polymerization applications, using a semi empirical Jain-Khare theoretical technique. Absolute partial cross sections for the formation of all fragment ions were measured by Jain-Khare method from threshold up to 120 eV. We obtained the following sixteen ions: CH3, Si, SiH, S...

Energy-transport models taking into account impact ionization are derived from a kinetic framework by formal asymptotic methods. The derivation is based on a system of Boltzmann transport equations governing the distribution functions of conduction electrons and holes in a semiconductor. The charge carriers are assumed to obey a degenerate gas statistics. The energy exchanged during collisions ...

Absolute measurements are presented for the positron-impact cross sections for positronium formation, direct ionization, and total ionization of the diatomic molecules N2, CO, and O2, in the range of energies from threshold to 90 eV. Cross sections for the electronic excitation of the a 1 and a 1 state in N2 and the A 1 state in CO near threshold are also presented. The experiment uses a cold, ...

To increase the responsivity is one of the vital issues for a photodetector. By employing ZnO as a representative material of ultraviolet photodetectors and Si as a representative material of visible photodetectors, an impact ionization process, in which additional carriers can be generated in an insulating layer at a relatively large electric field, has been employed to increase the responsivi...

Two-dimensional simulation of turn-on characteristics of GaAs MESFETs is performed in which surface states and impact ionization of carriers are considered. It is shown that the gate-lag (or the slow current transient) becomes weaker when including the impact ionization. This is attributed to the fact that the potential profiles along the surface is drastically changed when the surface states c...

Promising material properties of GaN, e.g., wide bandgap, high saturation velocity, and high thermal stability, make it an excellent material for high-power, high-frequency, and high-temperature applications. For some specific applications which require the device to operate at elevated temperatures, modeling and simulation provide very meaningful insights about the thermal device behavior. In ...

We calculate electron-hole generation and recombination rates for Coulomb scattering (Auger recombination and impact ionization) in Graphene. The conduction and valence band dispersion relation in Graphene together with energy and momentum conservation requirements restrict the phase space for Coulomb scattering so that electron-hole recombination times can be much longer than 1 ps for electron...