Dual-wavelength pump-probe measurements on helium-plasma-grown InGaAsP reveal complex carrier dynamics

Fundamental researches and explorations based on transition metal dichalcogenides (TMDCs) mainly focus on their monolayer counterparts, where optical densities are limited owing to the atomic monolayer thickness. Photoluminescence (PL) yield in bilayer TMDCs is much suppressed owing to indirect-bandgap properties. Here, optical properties are explored in artificially twisted bilayers of molybdenum disulfide (MoS2). Anomalous interlayer coupling and resultant giant PL enhancement are firstly observed in MoS2 bilayers, related to the suspension of the top layer material and independent of twisted angle. Moreover, carrier dynamics in MoS2 bilayers with anomalous interlayer coupling are revealed with pump-probe measurements, and the secondary rising behavior in pump-probe signal of B-exciton resonance, originating from valley depolarization of A-exciton, is firstly reported and discussed in this work. These results lay the groundwork for future advancement and applications beyond TMDCs monolayers.

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Mid-Infrared Pump-Probe Measurements of Carrier Dynamics in Black Phosphorus

Frontiers in Optics 2017 ◽

10.1364/fio.2017.jtu3a.31 ◽

2017 ◽

Author(s):

Yigit Aytac ◽

Martin Mittendorff ◽

Thomas E. Murphy

Keyword(s):

Carrier Dynamics ◽

Black Phosphorus ◽

Pump Probe ◽

Mid Infrared ◽

Probe Measurements

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Probing of Carrier Recombination in n- and p-Type 6H-SiC Using Ultrafast Supercontinuum Pulses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.821-823.245 ◽

2015 ◽

Vol 821-823 ◽

pp. 245-248 ◽

Cited By ~ 1

Author(s):

Paulius Grivickas ◽

Stephen Sampayan ◽

Kipras Redeckas ◽

Mikas Vengris ◽

Vytautas Grivickas

Keyword(s):

Carrier Dynamics ◽

Pump Probe ◽

Absorption Component ◽

Carrier Trapping ◽

Carrier Recombination ◽

Recombination Processes ◽

Background Doping ◽

P Type ◽

Excess Hole ◽

Probe Measurements

Excess carrier dynamics in 6H-SiC substrates with n- and p-type moderate doping were detected using femtosecond pump-probe measurements with supercontinuum probing. Band-to-band recombination and carrier trapping were determined as the main recombination processes in both materials. Spectral fingerprints corresponding to each of these recombination components were obtained using the global and target analysis. It was shown that, in spite of background doping, the band-to-band recombination in 6H-SiC is dominated by the excess electron absorption component and the carrier trapping is dominated by the excess hole absorption.

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Dual wavelength-swept fibre ring laser for wavelength-dependent pump-probe measurements

Electronics Letters ◽

10.1049/el:20071800 ◽

2007 ◽

Vol 43 (23) ◽

pp. 1263 ◽

Cited By ~ 3

Author(s):

J.-H. Han ◽

J.U. Kang

Keyword(s):

Ring Laser ◽

Dual Wavelength ◽

Pump Probe ◽

Fibre Ring ◽

Fibre Ring Laser ◽

Probe Measurements

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Pump-Probe Measurements Using Silicon Nanocrystal Waveguides

MRS Proceedings ◽

10.1557/proc-770-i3.2 ◽

2003 ◽

Vol 770 ◽

Cited By ~ 1

Author(s):

Nathanael Smith ◽

Max J. Lederer ◽

Marek Samoc ◽

Barry Luther-Davies ◽

Robert G. Elliman

Keyword(s):

Probe Beam ◽

Time Resolution ◽

Pump Beam ◽

Silicon Nanocrystals ◽

Continuous Wave ◽

Optical Gain ◽

Optical Pump ◽

Time Resolved ◽

Pump Probe ◽

Probe Measurements

AbstractOptical pump-probe measurements were performed on planar slab waveguides containing silicon nanocrystals in an attempt to measure optical gain from photo-excited silicon nanocrystals. Two experiments were performed, one with a continuous-wave probe beam and a pulsed pump beam, giving a time resolution of approximately 25 ns, and the other with a pulsed pump and probe beam, giving a time resolution of approximately 10 ps. In both cases the intensity of the probe beam was found to be attenuated by the pump beam, with the attenuation increasing monotonically with increasing pump power. Time-resolved measurements using the first experimental arrangement showed that the probe signal recovered its initial intensity on a time scale of 45-70 μs, a value comparable to the exciton lifetime in Si nanocrystals. These data are shown to be consistent with an induced absorption process such as confined carrier absorption. No evidence for optical gain was observed.

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