We induce surface carrier densities up to ∼ ⋅ 7 1014 cm−2 in few-layer graphene devices by electric double layer gating with a polymeric electrolyte. In 3-, 4and 5-layer graphene below 20–30 K we observe a logarithmic upturn of resistance that we attribute to weak localization in the diffusive regime. By studying this effect as a function of carrier density and with ab initio calculations we de...

The reduction of myocardial beta-adrenoceptor density in congestive heart failure has been thought to be caused by agonistinduced homologous desensitization. However, recent evidence suggests that excessive adrenergic stimulation may not produce myocardial beta-receptor downregulation unless there is an additional defect in the local norepinephrine (NE) uptake mechanism. To investigate the asso...

Structural inversion asymmetry controls the magnitude of Rashba spin-orbit coupling in the electron energy spectrum of a narrow band gap semiconductor. We investigate this effect for a series of two-dimensional electron gases in In0.52Ga0.48As quantum wells, surrounded by In0.52Al0.48As barriers, where either one or two electric subbands are populated. Structural inversion asymmetry does not ex...

The dynamics of charge transfer at interfaces are fundamental to the understanding of many processes, including light conversion to chemical energy. Here, we report imaging of charge carrier excitation, transport, and recombination in a silicon p-n junction, where the interface is well defined on the nanoscale. The recorded images elucidate the spatiotemporal behavior of carrier density after o...

The reflectance of highly reduced SrTiO32x has been studied in samples where the carrier concentration—or oxygen-vacancy density — varies from about 10 to 10 cm. Several phonon modes are strongly influenced by oxygen-vacancy density. Oxygen reduction induces a mid-infrared band whose oscillator strength scales with carrier density. In highly reduced samples, a weakly localized plasmon mode deve...

We performed combined magnetotransport and cyclotron resonance experiments on two-dimensional electron systems confined in the Mg(x)Zn(1-x)O/ZnO heterostructures over a wide range of carrier densities, from 1.9 to 12 × 10(11) cm(-2) (3.5 </~ r(s) </~ 10, where r(s) is the Wigner-Seitz radius). As the carrier density was reduced, the transport mass m(tr)* was strongly enhanced. In marked contras...

How to accurately determine carrier mobility and density in organic semiconducting materials is a very important subject for their optoelectronic applications including light-emitting diodes, solar cells, and thin film field-effect transistors. In this work, we report on a unique data analysis procedure for space-charge limited currents to simultaneously obtain the carrier density and mobility ...

A fully quantum-mechanical model for carrier scattering transport in semiconductor intersubband devices was applied to modelling of carrier dynamics in quantum cascade lasers. The standard model uses the envelope function and effective mass approximations to solve electron band structure under an applied bias. The k ·p model has been employed in p-type systems where the more complex band struct...