The elimination of extrinsic sources of spin relaxation is key to realizing the exceptional intrinsic spin transport performance of graphene. Toward this, we study charge and spin transport in bilayer graphene-based spin valve devices fabricated in a new device architecture that allows us to make a comparative study by separately investigating the roles of the substrate and polymer residues on ...

We present an empirical model for the electron energy relaxation time. It is based on Monte-Carlo simulation results and is applicable to all relevant diamond and zinc-blende structure semiconductors. The energy relaxation times are expressed as functions of the carrier and lattice temperatures, and in the case of semiconductor alloys, of the material composition. # 1999 Elsevier Science Ltd. A...

Carrier behavior in halide perovskite is a critical factor impacting on the properties of material, and finally determines performance photovoltaic luminescent devices. It necessary to clarify mechanism carrier relaxation migration at extremely microscopic time scale. Time-resolved spectroscopy provides powerful means for detection ultrafast processes, which has been an indispensable technique ...

In this study, we carried out 800-nm pump and ultra-broadband mid-infrared (MIR) probe spectroscopy with high time-resolution (70 fs) in bulk Ge. By fitting the time-resolved difference reflection spectra [ΔR(ω)/R(ω)] with the Drude model in the 200-5000 cm-1 region, the time-dependent plasma frequency and scattering rate have been obtained. Through the calculation, we can further get the time-...

We investigate the effects of reduced exciton diffusion on the emission properties in InGaN/GaN multiple-quantum-well nanorods. Time-resolved photoluminescence spectra are recorded and compared in dry-etched InGaN/GaN nanorods and parent multiple quantum wells at various temperatures with carrier density in different regimes. Faster carrier recombination and absence of delayed rise in the emiss...

We have studied the ultrafast optical response of native-oxide terminated Si~001! with pump-probe reflectivity using 800 nm, 28 fs pulses at an excitation density of (5.560.3)310 cm. Time-dependent reflectivity changes comprise third-order-response coherent-transient variations arising from anisotropic state filling and linear-response variations arising from excited free carriers, state fillin...

We characterize size-dependent carrier relaxation dynamics of partial laser structures containing quantum dashes by time-resolved degenerate four wave mixing between 1.2 and 1.6 mm. & 2010 Elsevier B.V. All rights reserved.

The carrier relaxation kinetics and nonlinear optical properties of strain-induced laterally ordered ~InP!2/~GaP!2 quantum wire ~QWR! samples were examined with time-resolved cathodoluminescence. A temperature dependence of the QWR luminescence decay time reveals that thermal activation of carriers in the QWR and transfer to and from In0.49Ga0.51P barriers plays an important role in determining...

We report a study of the relaxation time of the restoration of the resistive superconducting state in single crystalline boron-doped diamond using amplitude-modulated absorption of (sub-)THz radiation (AMAR). The films grown on an insulating diamond substrate have a low carrier density of about 2.5 × 1021 cm−3 and a critical temperature of about 2 K. By changing the modulation frequency we find...