Neutral scatterers dominate carrier transport in CVD graphene with ionic impurities

Electrochemical deposition of cobalt nanoparticles was used to modify carrier transport properties of single-layered CVD graphene at the SiO2-on-Si substrate. The structure of graphene with cobalt nanoparticles was analyzed by Raman spectroscopy and scanning electron microscopy. The effect of the deposited cobalt nanoparticles on the sheet resistance of graphene was studied in the temperature range of 4–300[Formula: see text]K.

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Effect of cobalt particle deposition on quantum corrections to Drude conductivity in twisted CVD graphene

Modern Electronic Materials ◽

10.3897/j.moem.5.4.52068 ◽

2019 ◽

Vol 5 (4) ◽

pp. 165-173

Author(s):

Alexander K. Fedotov ◽

Sergey L. Prishchepa ◽

Alexander S. Fedotov ◽

Vladzislaw E. Gumennik ◽

Ivan V. Komissarov ◽

...

Keyword(s):

Magnetic Field ◽

Quantum Interference ◽

Particle Deposition ◽

Carrier Transport ◽

Ohmic Contacts ◽

Weak Localization ◽

Thermal Fluctuations ◽

Field Range ◽

Cvd Graphene ◽

Graphene Layers

Graphene applications in electronics require experimental study of the formation of high-quality Ohmic contacts and deeper understanding of electron transport mechanisms at metal/grapheme contacts. We have studied carrier transport in twisted CVD graphene decorated with electrodeposited Co particles forming Ohmic contacts with graphene layers. We have compared layer resistivity as a function of temperature and magnetic field R�(T, B) for as-synthesized and decorated twisted graphene on silicon oxide substrates. Experiments have proven the existence of negative (induction < 1 Tl) and positive (induction > 1 Tl) contributions to magnetoresistance in both specimen types. The R�(T, B) functions have been analyzed based on the theory of 2D quantum interference corrections to Drude conductivity taking into account competition of hopping conductivity mechanism. We show that for the experimental temperature range (2–300 K) and magnetic field range (up to 8 Tl), carrier transport description in test graphene requires taking into account at least three interference contributions to conductivity, i.e., from weak localization, intervalley scattering and pseudospin chirality, as well as graphene buckling induced by thermal fluctuations.

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Lifetime Regime in the Electrically-Detected Transient Grating Method Applied to Amorphous and Microcrystalline Silicon Films

MRS Proceedings ◽

10.1557/proc-715-a20.2 ◽

2002 ◽

Vol 715 ◽

Cited By ~ 1

Author(s):

P. Sanguino ◽

M. Niehus ◽

S. Koynov ◽

P. Brogueira ◽

R. Schwarz ◽

...

Keyword(s):

Carrier Transport ◽

Analytical Calculation ◽

Chemical Vapor ◽

Silicon Films ◽

Dielectric Relaxation Time ◽

Transient Grating ◽

Minority Carrier Diffusion Length ◽

Carrier Recombination ◽

Thin Silicon ◽

Good Agreement

AbstractThe minority-carrier diffusion length in thin silicon films can be extracted from the electrically-detected transient grating method, EDTG, by a simple ambipolar analysis only in the case of lifetime dominated carrier transport. If the dielectric relaxation time, τdiel, is larger than the photocarrier response time, τR, then unexpected negative transient signals can appear in the EDTG result. Thin silicon films deposited by hot-wire chemical vapor deposition (HWCVD) near the amorphous-to-microcrystalline transition, where τR varies over a large range, appeared to be ideal candidates to study the interplay between carrier recombination and dielectric response. By modifying the ambipolar description to allow for a time-dependent carrier grating build-up and decay we can obtain a good agreement between analytical calculation and experimental results.

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