Probing the ultrafast dynamics of excitons in single semiconducting carbon nanotubes

Birkmeier, Konrad; Hertel, Tobias; Hartschuh, Achim

doi:10.1038/s41467-022-33941-2

Cited by 13 publications

(7 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even though the impact of substrate passivation on charge transport in these devices is not significant, the improvement of the EL spectra is striking. This difference can be attributed to the high mobility of excitons in individual nanotubes and in dense networks, [60][61][62] as they are not confined to the semiconductor/dielectric interface by the electric field as opposed to the charge carriers. As such, excitons are much more sensitive to even a few defect sites within the SWCNT network and the nanotube-substrate interface.…”

Section: Resultsmentioning

confidence: 99%

Near‐Intrinsic Photo‐ and Electroluminescence from Single‐Walled Carbon Nanotube Thin Films on BCB‐Passivated Surfaces

Zorn

Settele

Zhao

et al. 2023

Advanced Optical Materials

View full text Add to dashboard Cite

Their outstanding electrical and optical properties make semiconducting single‐walled carbon nanotubes (SWCNTs) highly suitable for charge transport and emissive layers in near‐infrared optoelectronic devices. However, the luminescence spectra of SWCNT thin films on commonly used glass and Si/SiO2 substrates are often compromised by broadening of the main excitonic emission and unwanted low‐energy sidebands. Surface passivation with a commercially available, low dielectric constant, cross‐linked bis‐benzocyclobutene‐based polymer (BCB) enhances the emission properties of SWCNTs to the same level as hexagonal boron nitride (h‐BN) flakes do. The presence of BCB suppresses sideband emission, especially from the Y1 band, which is attributed to defects introduced by the interaction of the nanotube lattice with oxygen‐containing terminal groups of the substrate surface. The facile and reproducible deposition of homogeneous BCB films over large areas combined with their resistance against common solvents and chemicals employed during photolithography make them compatible with standard semiconductor device fabrication. Utilizing this approach, light‐emitting (6,5) SWCNT network field‐effect transistors are fabricated on BCB‐treated glass substrates with excellent electrical characteristics and near‐intrinsic electroluminescence. Hence, passivation with BCB is proposed as a standard treatment for substrates used for spectroscopic investigations of and optoelectronic devices with SWCNTs and other low‐dimensional emitters.

show abstract

Section: Resultsmentioning

confidence: 99%

Near‐Intrinsic Photo‐ and Electroluminescence from Single‐Walled Carbon Nanotube Thin Films on BCB‐Passivated Surfaces

Zorn

Settele

Zhao

et al. 2023

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…An accessible and commonly used nanotube species for both spectroscopic − as well as charge transport studies − are (6,5) SWCNTs, which can be obtained in sufficient quantities through various separation techniques including polymer wrapping using poly[(9,9-dioctylfluorenyl-2,7-diyl)- alt -(6,6′-(2,2′-bipyridine))] (PFO-BPy) . The relatively large band gap and narrow E 11 excitonic transition of (6,5) nanotubes around 1.24 eV enable easy detection even of further red-shifted trion emission.…”

Section: Introductionmentioning

confidence: 99%

Impact of Dielectric Environment on Trion Emission from Single-Walled Carbon Nanotube Networks

et al. 2023

View full text Add to dashboard Cite

Trions are charged excitons that form upon optical or electrical excitation of low-dimensional semiconductors in the presence of charge carriers (holes or electrons). Trion emission from semiconducting single-walled carbon nanotubes (SWCNTs) occurs in the near-infrared and at lower energies compared to the respective exciton. It can be used as an indicator for the presence of excess charge carriers in SWCNT samples and devices. Both excitons and trions are highly sensitive to the surrounding dielectric medium of the nanotubes, having an impact on their application in optoelectronic devices. Here, the influence of different dielectric materials on exciton and trion emission from electrostatically doped networks of polymersorted (6,5) SWCNTs in top-gate field-effect transistors is investigated. The observed differences of trion and exciton emission energies and intensities for hole and electron accumulation cannot be explained with the polarizability or screening characteristics of the different dielectric materials, but they show a clear dependence on the charge trapping properties of the dielectrics. Charge localization (trapping of holes or electrons by the dielectric) reduces exciton quenching, emission blue-shift and trion formation. Based on the observed carrier type and dielectric material dependent variations, the ratio of trion to exciton emission and the exciton blue-shift are not suitable as quantitative metrics for doping levels of carbon nanotubes.

show abstract

“…In contrast, other studies have favored an inhomogeneous description, specifically regarding electronic transport phenomena or the mechanism of NR exciton decay. ,− Such models were particularly successful in describing the dependence of fluorescence quantum yields in SWNTs on nanotube length, ,,− the effect of defects on PL-imaging of SWNTs, , and the influence of diffusive exciton transport on NR decay observed in time-domain investigations of exciton dynamics. ,− Moreover, localization of excess charge carriers has also been instrumental for the interpretation of Breit–Wigner–Fano resonances in the IR spectra of doped SWNTs. , …”

Section: Introductionmentioning

confidence: 99%

Trions, Exciton Dynamics, and Spectral Modifications in Doped Carbon Nanotubes: A Singular Defect-Driven Mechanism

Eckstein,

Kunkel,

Voelckel

et al. 2023

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

Doping substantially influences the electronic and photophysical properties of semiconducting single-walled carbon nanotubes (s-SWNTs). Although prior studies have noted that surplus charge carriers modify optical spectra and accelerate nonradiative exciton decay in doped s-SWNTs, a direct mechanistic correlation of trion formation, exciton dynamics, and energetics remains elusive. This work examines the influence of doping-induced nonradiative decay and exciton confinement on s-SWNT photophysics. Using photoluminescence, continuous-wave absorption, and pump–probe spectroscopy, we show that localization of and barrier formation by trapped charges can be jointly quantified using diffusive exciton transport and particle-in-the-box models, yielding a one-to-one correlation between charge carrier concentrations derived from these models. The study highlights the multifaceted role of exohedral counterions, which trap charges to create quenching sites, form barriers to exciton movement, and host trion states. This contributes significantly to understanding and optimizing the photophysical properties of doped SWNTs.

show abstract

Probing the ultrafast dynamics of excitons in single semiconducting carbon nanotubes

Cited by 13 publications

References 54 publications

Near‐Intrinsic Photo‐ and Electroluminescence from Single‐Walled Carbon Nanotube Thin Films on BCB‐Passivated Surfaces

Near‐Intrinsic Photo‐ and Electroluminescence from Single‐Walled Carbon Nanotube Thin Films on BCB‐Passivated Surfaces

Impact of Dielectric Environment on Trion Emission from Single-Walled Carbon Nanotube Networks

Trions, Exciton Dynamics, and Spectral Modifications in Doped Carbon Nanotubes: A Singular Defect-Driven Mechanism

Contact Info

Product

Resources

About