Contactless Optical Characterization of Carrier Dynamics in Free-Standing InAs-InAlAs Core–Shell Nanowires on Silicon

Li, Xinxin; Zhang, Kailing; Treu, Julian; Stampfer, Lukas; Koblmueller, Gregor; Toor, Fatima; Prineas, J. P.

doi:10.1021/acs.nanolett.8b04226

Cited by 17 publications

(13 citation statements)

References 51 publications

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“…This has a much stronger dependence on the carrier concentration and is often an undesirable process in systems involving high-carrier-density applications such as lasers. The rate constants for this mechanism are often in the range of 10 –26 – 10 –31 cm 6 s –1 (see refs ,− and references therein). The recombination rates for the mechanisms mentioned above have been measured through various experimental techniques, including transient absorption spectroscopy.…”

Section: Resultsmentioning

confidence: 99%

“…The recombination coefficients for the SRH and biomolecular mechanisms appear consistent with earlier reported measurements on different semiconductors. 18,[48][49][50]63 The results reported here are crucial to enhance our understanding of the recombination processes in hBN, which will help to tailor the optoelectronic properties to increase the quantum efficiency of hBN-based devices.…”

Section: ■ Conclusionmentioning

confidence: 92%

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Auger Recombination Kinetics of the Free Carriers in Hexagonal Boron Nitride

Sharma,

Liu,

Edgar

et al. 2023

ACS Photonics

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Hexagonal boron nitride (hBN) is a wide indirect bandgap semiconductor with a strong luminescence that is many orders of magnitude higher than diamond. It holds great promise for optoelectronic devices over a wide frequency range spanning from ultraviolet (UV) to mid-infrared (IR). Auger recombination, a nonradiative mechanism, is one of the three mechanisms that determine the kinetics of the photoexcited carriers and strongly contributes to losses in quantum efficiency. Here, we report on the dynamics of photogenerated free carriers in exfoliated 10B-enriched (99%) hBN at room temperature. We identified Auger and defect-assisted recombination mechanisms experimentally by utilizing ultrafast transient absorption spectroscopy. Recombination at high carrier densities occurs via an Auger process with a characteristic rate constant in the range of 10–24 to 10–26 cm6/s with a strong dependence on the excitation fluence. A slower recombination mechanism independent of the excitation fluence at a rate of ∼5.6 × 109 s–1 was assigned to Shockley–Read–Hall (SRH) defects.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Conclusionmentioning

confidence: 92%

Auger Recombination Kinetics of the Free Carriers in Hexagonal Boron Nitride

Sharma,

Liu,

Edgar

et al. 2023

ACS Photonics

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“…This means that probe energies in the mid-IR are far more sensitive to free carriers than probe energies above the gap. The excitation intensity dependent decay can be well described with the common ABC Model which utilizes Auger, radiative and Shockley-Read-Hall recombination 11 . At high excitation intensities, a larger carrier density is excited which causes larger recombination rates due to carrier-carrier interactions such as Auger recombination which involves three particles.…”

Section: Discussionmentioning

confidence: 99%

Time resolved infrared spectroscopy for hot carrier dynamics in InAs-AlAsSb core-shell nanowires

Daniel¹,

Esmaielpour²,

Giudice³

et al. 2023

Physics, Simulation, and Photonic Engineering of Photovoltaic Devices XII

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Semiconductor nanowires (NWs) have shown robust hot carrier effects due to their small dimensions. Here, we study the cooling mechanisms of hot electrons in the time domain via transient absorption spectroscopy. Probe energies below the bandgap are used to determine the evolution of the carrier effective mass while probe energies above the bandgap track the conduction band occupation. From excitation intensity dependent measurements, we confirm that electron-hole interactions are a major cooling channel at large carrier density, given the high ratio of mh/me of InAs. Our experiments indicate that this cooling channel is amplified in passivated core-shell NWs. We associate this effect with spatial carrier separation caused by Fermi-level pinning in unpassivated NWs. In core-shell NWs, bands are considerably more flat which increases radiative recombination and electron-hole scattering with the latter cooling the hot electron population. Our results highlight the advantages of carrier separation if high carrier densities are to be used for hot phonon bottlenecks.

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“…Such photoexcited carriers exist in the semiconductor for a certain amount of time (their lifetime) and induce a change in the transmitted THz power and resonance frequency. Such a pump‐probe structure is commonly used for optical characterization of carrier dynamics, but it can also be used to attenuate or filter THz waves if sufficient electron–hole pairs are pumped. A good example of optically tunable THz bandpass metamaterials based on a semiconductor was presented by Hoeh and co‐workers .…”

Section: Modulation Methods Of Thz Transmission Resonancementioning

confidence: 99%

Design, Fabrication, and Modulation of THz Bandpass Metamaterials

Wang

Gao

Raglione

et al. 2019

Laser & Photonics Reviews

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Development of terahertz (THz) sources, detectors, and optical components has been an active area of research across the globe. The interest in THz optoelectronics is driven by the various applications they have enabled, such as ultrawide‐band communication systems, air‐ and space‐borne astronomy, atmospheric monitoring, small‐scale radar, airport security scanners, ultrafast nanodevices, and biomedical imaging and sensing. Here, the aim is to provide a comprehensive review of THz bandpass metamaterials focusing on several areas. First, the design fundamentals and geometrical patterns of THz bandpass metamaterials are summarized. Second, fabrication methods of THz bandpass metamaterials are reviewed, including typical micro‐ and nanofabrication techniques and laser micromachining techniques. More importantly, different engineering methods are reviewed for tuning and modulation of the THz transmission resonance for these metamaterials. Both passive and active modulation methods are included in this discussion; the passive method involves changes in the geometrical pattern of the filter material, and the active method performs in situ modulation of properties by applying an external physical field. Finally, the potential applications and prospects for future research of THz bandpass metamaterials are discussed.

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Contactless Optical Characterization of Carrier Dynamics in Free-Standing InAs-InAlAs Core–Shell Nanowires on Silicon

Cited by 17 publications

References 51 publications

Auger Recombination Kinetics of the Free Carriers in Hexagonal Boron Nitride

Auger Recombination Kinetics of the Free Carriers in Hexagonal Boron Nitride

Time resolved infrared spectroscopy for hot carrier dynamics in InAs-AlAsSb core-shell nanowires

Design, Fabrication, and Modulation of THz Bandpass Metamaterials

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