arXiv subjects

Jaroslaw Klos

Publications and source records attributed to Jaroslaw Klos.

4 recordsLinked to original sources

arXiv2009

Two-dimensional GaAs/AlGaAs superlattice structures for solar cell applications: ultimate efficiency estimation

We calculate the band structure of a two-dimensional GaAs/AlGaAs superlattice and estimate the ultimate efficiency of solar cells using this type of structure for solar energy conversion. The superlattice under consideration consists of gallium arsenide rods forming a square lattice and embedded in aluminium gallium arsenide. The ultimate efficiency is determined versus structural parameters including the filling fraction, the superlattice constant, the rod geometry and the concentration of Al in the matrix material. The calculated efficiency of the superlattice proves to exceed the efficiency of each component material in the monolithic state in a wide range of parameter values.

cond-mat.mes-hall↗

arXiv2009

Surface states in zigzag and armchair graphene nanoribbons

This paper presents electronic spectra of zigzag and armchair graphene nanoribbons calculated within the tight-binding model for pi-electrons. Zigzag and armchair nanoribbons of different edge geometries are considered, with surface perturbation taken into account. The properties of surface states are discussed on the basis of their classification into Tamm states and Shockley states. In armchair nanoribbons surface states are shown to close the energy gap at the Dirac point for certain edge geometries.

cond-mat.mes-hall↗

arXiv2006

The effect of electron-electron interactions on the conditions of surface state existence

Electronic surface states in one-dimensional two-band TBA model are studied by use of the Green function method. The local density of states (LDOS) at successive atoms in a semi-infinite chain, even in the case of atoms distant from the surface, is found to be clearly different from that observed in an unperturbed (infinite) chain. The surface atom occupancy is calculated self-consistently, with the effect of electron-electron interactions taken into account. The electron-electron interactions are shown to have a significant impact on the conditions of surface state existence.

cond-mat.mes-hall↗

arXiv2006

Electron states in the quantum wire with periodic serial structure

A model quantum wire embedded in a matrix permeable to electron waves is investigated in terms of electronic states. The wire is assumed to have a 1D crystal structure. Through electron waves propagating in its surroundings, lateral modes are coupled with Bloch waves propagating along the wire axis, which results in modes splitting into multiplets. The results presented in this study have been obtained by direct solution of the Schrodinger equation in the effective mass approximation.

cond-mat.mes-hall↗