Relative stability of excitonic complexes in quasi-one-dimensional semiconductors

Bondarev, I. V.

doi:10.1103/physrevb.90.245430

Cited by 18 publications

(15 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because of its being localized in a deep trap, a defect-state trion is expected to have a larger binding energy due to enhanced Coulomb interactions between the exciton and electron. 37…”

Section: Results and Discussionmentioning

confidence: 99%

Probing Trions at Chemically Tailored Trapping Defects

et al. 2019

View full text Add to dashboard Cite

Trions, charged excitons that are reminiscent of hydrogen and positronium ions, have been intensively studied for energy harvesting, light-emitting diodes, lasing, and quantum computing applications because of their inherent connection with electron spin and dark excitons. However, these quasi-particles are typically present as a minority species at room temperature making it difficult for quantitative experimental measurements. Here, we show that by chemically engineering the well depth of sp3 quantum defects through a series of alkyl functional groups covalently attached to semiconducting carbon nanotube hosts, trions can be efficiently generated and localized at the trapping chemical defects. The exciton-electron binding energy of the trapped trion approaches 119 meV, which more than doubles that of “free” trions in the same host material (54 meV) and other nanoscale systems (2–45 meV). Magnetoluminescence spectroscopy suggests the absence of dark states in the energetic vicinity of trapped trions. Unexpectedly, the trapped trions are approximately 7.3-fold brighter than the brightest previously reported and 16 times as bright as native nanotube excitons, with a photoluminescence lifetime that is more than 100 times larger than that of free trions. These intriguing observations are understood by an efficient conversion of dark excitons to bright trions at the defect sites. This work makes trions synthetically accessible and uncovers the rich photophysics of these tricarrier quasi-particles, which may find broad implications in bioimaging, chemical sensing, energy harvesting, and light emitting in the short-wave infrared.

show abstract

“…Because of its being localized in a deep trap, a defect-state trion is expected to have a larger binding energy due to enhanced Coulomb interactions between the exciton and electron. 37…”

Section: Results and Discussionmentioning

confidence: 99%

Probing Trions at Chemically Tailored Trapping Defects

et al. 2019

View full text Add to dashboard Cite

show abstract

“…This is quite similar to what was reported earlier for quasi-1D biexciton and trion systems. 96 For compound quasi-1D exciton systems this is a generic feature resulted from the fact that greater µ, while not affecting significantly the single charge tunnel exchange in the trion complex, make the neutral biexciton complex generally more compact to facilitate the mixed charge tunnel exchange in it and thus to make the biexciton binding energy greater than that of the trion. This feature is suppressed in quasi-2D complexes of indirect excitons due to their long-range dipolar repulsion, which is absent from the trion complex to keep its binding energy always being greater than that of the biexciton as one can see in Fig.…”

Section: Charge-coupled Indirect Excitonmentioning

confidence: 99%

“…The configuration space approach was originally pioneered by Landau,101 Gor'kov and Pitaevski, 102 Holstein and Herring 103 in their studies of molecular binding and mag-netism. The method has been shown to be especially advantageous in the case of quasi-1D semiconductors, 91,96 where it offers easily tractable, complete analytical solutions to reveal universal asymptotic relations between the binding energy of the complex of interest and the binding energy of the exciton in the same nanostructure. In this approach, the trion or biexciton bound state forms due to the exchange under-barrier tunneling between the equivalent configurations of the electron-hole system in the configuration space.…”

Section: Introductionmentioning

confidence: 99%

Complexes of dipolar excitons in layered quasi-two-dimensional nanostructures

Bondarev

Vladimirova

2018

Phys. Rev. B

View full text Add to dashboard Cite

We discuss neutral and charged complexes (biexciton and trion) formed by indirect excitons in layered quasi-two-dimensional semiconductor heterostructures. Indirect excitons -long-lived neutral Coulomb-bound pairs of electrons and holes of different layers -have been known for semiconductor coupled quantum wells and are recently reported for van der Waals heterostructures such as bilayer graphene and transition metal dichalcogenides. Using the configuration space approach, we derive the analytical expressions for the trion and biexciton binding energies as functions of the interlayer distance. The method captures essential kinematics of complex formation to reveal significant binding energies, up to a few tens of meV for typical interlayer distances ∼ 3 − 5Å, with the trion binding energy always being greater than that of the biexciton. Our results can contribute to the understanding of more complex many-body phenomena such as exciton Bose-Einstein condensation and Wigner-like electron-hole crystallization in layered semiconductor heterostructures.I.

show abstract

“…34 Since our first observation of the trion state in 2011, 34 theoretical and experimental studies on trions have been carried out extensively. [43][44][45][46][47][48][49][50][51][52] Trion states are confirmed by various doping methods such as chemical doping, 34,44,45 photoexcitation, 43 electrochemical technique, 46 and electrostatic gating. 47 Under strong photoexcitation conditions, dissociated carriers resulting from Auger recombination can create trion states with a subsequent absorbed photon.…”

mentioning

confidence: 99%

Review—Photophysics of Trions in Single-Walled Carbon Nanotubes

Nishihara¹,

Okano²,

Yamada³

et al. 2017

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

The photophysics of trions in single-walled carbon nanotubes (SWCNTs) is reviewed briefly. The trion state is observed energetically below the exciton state in hole-doped SWCNTs, and shows a simple single-exponential decay. The decay dynamics of trions depends on the photoexcitation condition. The optical responses of trions can be discussed by considering the energy relaxation of the optically accessible trion state. Detailed studies of excitons, trions, and biexcitons provide a deep understanding of the material properties of SWCNTs and are required for the design of photonic devices based on SWCNTs. 3,4 which has led to accelerated experimental studies on various optical properties of SWCNTs. Electrons and holes are strongly spatially confined to diameters on the order of 1 nm, resulting in room temperature stable excitons with large binding energies in the range of 200-400 meV.5-11 The exciton dynamics thus dominates the optical properties of semiconducting SWCNTs. 5,6 High-quality carbon nanomaterials provide an excellent experimental stage for studies on photophysics of excitons and exciton complexes.The exciton structures in SWCNTs are complicated due to the intrinsic properties of graphene, their unique helical structures, and coulomb interactions. 5 The origin of the optical absorption and PL is ascribed to the dipole-allowed (bright) exciton states, and their dynamics are affected by the interplay with the dipole-forbidden (dark) exciton states. Single nanotube spectroscopy has revealed details of the intrinsic exciton properties. For example, magneto-optical studies showed that the even-parity singlet dark exciton state is located energetically below the bright exciton state.12,13 Thermalization between the bright and dark exciton states determines the temperaturedependent PL properties 12,13 and the exciton diffusion length. 14,15 Furthermore, strong spatial confinement accentuates the exciton-exciton and exciton-electron interactions. Time-resolved transient absorption (TA) and PL spectroscopy measurements have revealed that multiple exciton states show rapid decays due to nonradiative Auger recombination. [16][17][18][19] Nonradiative Auger recombination, which competes with exciton diffusion, determines the PL efficiency of semiconducting SWCNTs, [20][21][22][23][24] and it ensures nonclassical PL by preventing the occupation of identical exciton states. 25Carrier doping is one of the most important techniques in semiconductors, which controls their electrical and optical properties. In SWCNTs, carrier doping has been actively studied using chemical modification [26][27][28][29][30][31][32][33][34][35][36][37] 47 Under strong photoexcitation conditions, dissociated carriers resulting from Auger recombination can create trion states with a subsequent absorbed photon. 43 Positive and negative trion states show almost the same binding energies. 46 Time-resolved TA and PL measurements have revealed fast formation of the trion state through the exciton-hole interaction. 48,49 Active experimental stud...

show abstract

Relative stability of excitonic complexes in quasi-one-dimensional semiconductors

Cited by 18 publications

References 43 publications

Probing Trions at Chemically Tailored Trapping Defects

Probing Trions at Chemically Tailored Trapping Defects

Complexes of dipolar excitons in layered quasi-two-dimensional nanostructures

Review—Photophysics of Trions in Single-Walled Carbon Nanotubes

Contact Info

Product

Resources

About