Naphthalene (N) or naphthalene-derivative (ND) adsorption-treatment evidently varies the electrical conductivity of single wall carbon nanotube (SWCNT) bundles over a wide temperature range due to a charge-transfer interaction. The adsorption treatment of SWCNTs with dinitronaphthalene molecules enhances the electrical conductivity of the SWCNT bundles by 50 times. The temperature dependence of...

It is shown that lines of adsorbed hydrogen pair atoms divide the graphene sheet into strips and form hydrogen-based superlattice structures (2HG-SL). We show that the forming of 2HG-SL drastically changes the electronic properties of graphene from semimetal to semiconductor. The electronic spectra of “zigzag” (n,0) 2HG-SL is similar to that of (n,0) carbon nanotubes and have a similar oscillat...

We demonstrate a technique for femtosecond time-resolved optical pump-probe spectroscopy that allows to scan over a nanosecond time delay at a kilohertz scan rate without mechanical delay line. Two mode-locked femtosecond lasers with approximately 1 GHz repetition rate are linked at a fixed difference frequency of fR=11 kHz. One laser delivers the pump pulses, the other provides the probe pulse...

We study the band and transport features of zigzag graphene nanoribbon with an antidot lattice. It is found that an antidot lattice could turn semi-metal graphene into a semiconductor. The size of the band gap can be tuned by the position of the antidots and the distance D between the two nearest antidots. For a finite superlattice with N antidots and a large D, a group of (N - 1) splitting res...

We report about the formation of a Si twinning-superlattice (TSL). Si layers containing 1808 rotation twin boundaries arranged periodical along the [111] direction and only separated by 2.5 nm (corresponding to TSL) have been prepared by molecular beam epitaxy. The method consists of repeating of several growth and annealing circles on boron(B)-predeposited undoped Si substrates. It is shown th...

The surface density of charge current in two-dimensional double-periodic n-type semiconductor superlattices is calculated the one-electron approximation an external magnetic field presence a temperature gradient. was assumed to be constant, uniform, applied perpendicular plane electron gas. joint solution Schrodinger equation and kinetic Boltzmann shown that dependence transverse about module g...

We have calculated the piezoelectric coupling between a two-dimensional electron gas and the stress field due to a lateral surface superlattice, a periodic striped gate. The stress is assumed to arise from differential contraction between the metal gate and semiconductor. The piezoelectric potential is several times larger than the deformation potential and generally gives the dominant coupling...

The coupling between Bloch oscillations and longitudinal optical (LO) phonons is investigated in ternary In0.53Ga0.47As / In0.52Al0.48As superlattices of different well widths. In femtosecond time-resolved studies, a strong increase of the coherent LO phonon amplitudes is observed when the Bloch oscillations are subsequently tuned into resonance with the different optical phonon modes of the te...