相关论文: Carrier density driven lasing dynamics in ZnO nano…
We study the effect of population inversion associated with the electron and hole injection in graphene p-i-n structures at the room and slightly lower temperatures. It is assumed that the recombination and energy relaxation of electrons…
The reflection and transmission of a few-cycle femtosecond Ti:Sa laser pulse impinging on a metal nano-layer have been analysed. The thickness of the layer was assumed to be of order of 2-10 nm, and the metallic free electrons were…
We present a model to describe the spatiotemporal evolution of guided modes in semiconductor nanowires based on a coupled mode formalism. Light-matter interaction is modelled based on semiconductor Bloch equations, including many-particle…
The new regime of low-temperature heat transfer in suspended nanowires is predicted. It takes place when (i) only ``acoustic'' phonon modes of the wire are thermally populated and (ii) phonons are subject to the effective elastic…
We apply the coupled dynamics of time-dependent density functional theory and Maxwell equations to the interaction of intense laser pulses with crystalline silicon. As a function of electromagnetic field intensity, we see several regions in…
The energy relaxation of carriers in reduced graphene oxide thin films is studied using optical pump-probe spectroscopy with two probes of different colors. We measure the time difference between peaks of the carrier density at each probing…
The structure-property relation of nanostructured Al-doped ZnO thin films has been investigated in detail through a systematic variation of structure and morphology, with particular emphasis on how they affect optical and electrical…
We report an optical study of the dynamics of photoexcited carriers in Si2Te3 nanowires at various temperatures and excitation powers. Si2Te3 nanowires were synthesized, by using gold as a catalyst, on a silicon substrate by the chemical…
Upon the excitation by an ultrashort laser pulse the conditions in a material can drastically change, altering its optical properties and therefore the relative amount of absorbed energy, a quan- tity relevant for determining the damage…
We theoretically investigate the generation of ultrafast currents in insulators induced by strong few-cycle laser pulses. Ab initio simulations based on time-dependent density functional theory give insight into the atomic-scale properties…
Understanding heat transport at the nanometer scale is critical for semiconductor devices, quantum materials, and thermal management of nanostructures, yet direct local measurements of thermal conductivity and heat capacity remain scarce.…
The thermal dynamics induced by ultrashort laser pulses in nanoscale systems, i.e. all-optical time-resolved nanocalorimetry is theoretically investigated from 300 to 1.5 K. We report ab-initio calculations describing the temperature…
The effective increase of the critical density associated with the interaction of relativistically intense laser pulses with overcritical plasmas, known as self-induced transparency, is revisited for the case of circular polarization. A…
We discuss the origin of the temperature dependence of resistivity observed in highly oriented LaNiO_3 thin films (of thickness d) grown on SrTiO_3 substrate by a pulsed laser deposition technique. All the experimental data are found to…
We have investigated ultrafast carriers dynamics in crystalline silicon nano-pillars structure using a pump-probe reflectivity method with 800 nm, 150 fs laser pulses and fluence in the range of {17 - 170} mJ/cm^2. Dimensions of the…
We report a transient absorption microscopy study of charge carrier dynamics in bulk MoS2 crystals at room temperature. Charge carriers are injected by interband absorption of a 555-nm pulse, and probed by measuring differential reflection…
The realization of semiconductors that are ferromagnetic above room temperature will potentially lead to a new generation of spintronic devices with revolutionary electrical and optical properties. Transition temperatures in doped ZnO are…
The dielectric properties of NiO thin films grown by pulsed laser deposition have been studied as a function of strain at temperature from 10 to 300 K. Above 150 K, the contribution of space-charge polarization to the dielectric…
Zinc Oxide thin films were grown on c-sapphire substrates using pulsed laser deposition. Pump power dependence of surface emission spectra, acquired using a quadrupled 266 nm laser, revealed room temperature stimulated emission (threshold…
Low resistivity (~3-24 mOhm.cm) with tunable n- and p-type phase pure Cu2O thin films have been grown by pulsed laser deposition at 25-200 0C by varying the background oxygen partial pressure (O2pp). Capacitance data obtained by…