Laser Action of Trions in a Semiconductor Quantum Well

Puls, J.; Mikhailov, G. V.; Henneberger, F.; Yakovlev, D. R.; Waag, A.; Faschinger, W.

doi:10.1103/physrevlett.89.287402

Cited by 20 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, although this quasi-particle was theoretically predicted by Lampert 8 as early as 1958, trions were not experimentally observed for decades until their recent identification by photoluminescence (PL) spectroscopy in low-dimensional semiconductors at cryogenic temperatures. 3,5,6,9 One of the key factors that fundamentally limits trions from being a dominant species is their low binding energy (2–45 meV). 5,9,10 In low-dimensional semiconductors, such as single-walled carbon nanotubes (SWCNTs) and atomically thin two-dimensional (2D) transition metal dichalcogenides, the binding energy of trions increases due to the stronger Coulomb interactions at reduced dimensionality, allowing trions to be detected at room temperature.…”

Section: Introductionmentioning

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

Section: Introductionmentioning

confidence: 99%

Probing Trions at Chemically Tailored Trapping Defects

et al. 2019

View full text Add to dashboard Cite

show abstract

“…However, due to the development of nanostructure technology, it is now possible to experimentally study these trions because, all binding energies being enhanced by the reduction of dimensionality, trions, not seen in bulk samples, can appear as line well below the exciton line in the absorption spectra of doped semiconductor quantum wells (see for instance ref. [3][4][5][6][7][8][9]).…”

Section: Introductionmentioning

confidence: 99%

The trion: two electrons plus one hole versus one electron plus one exciton

2004

View full text Add to dashboard Cite

We first show that, for problems dealing with trions, it is totally hopeless to use the standard many-body description in terms of electrons and holes and its associated Feynman diagrams. We then show how, by using the description of a trion as an electron interacting with an exciton, we can obtain the trion absorption through far simpler diagrams, written with electrons and excitons. These diagrams are quite novel because, for excitons being not exact bosons, we cannot use standard procedures designed to deal with interacting true fermions or true bosons. A new many-body formalism is necessary to establish the validity of these electron-exciton diagrams and to derive their specific rules. It relies on the "commutation technique"we recently developed to treat interacting close-to-bosons. This technique generates a scattering associated to direct Coulomb processes between electrons and excitons and a dimensionless "scattering" associated to electron exchange inside the electronexciton pairs -this "scattering" being the original part of our many-body theory.It turns out that, although exchange is crucial to differentiate singlet from triplet trions, this "scattering" enters the absorption explicitly when the photocreated electron and the initial electron have the same spini. e., when triplet trions are the only ones createdbut not when the two spins are different, although triplet trions are also created in this case. The physical reason for this rather surprising result will be given.

show abstract

“…Recent study (7) shows an interesting relationship between the Mott density (MD) and the transparency density, at which optical gain or stimulated emission occurs, especially in low dimensional systems. Limited study of the stimulated emission through excitonic complexes in the intermediate density regimes has produced both scientific discoveries and technological breakthroughs in semiconductor photonics research, such as optical gain based on excitons (8,9), bi-excitons (10,11), trions (12,13), and polariton-scatterings (14) in III-V or II-VI compound semiconductors, or multi-exciton (15) and single-exciton (16) gain observed in nanocrystals. These relatively rare gain mechanisms have resulted lasing demonstrations at much lower pumping thresholds than conventional lasers which require higher pumping above MD.…”

mentioning

confidence: 99%

“…This behavior and the relative spectral features strongly suggest that the optical gain originates from trions. The physical mechanism of trionic gain was first studied in doped ZnSe quantum wells (12). According to this understanding, the trion system can be described by a "two-band" model: a ground state of a doped (e.g., n-type) material which is the conduction band, Ee, filled with a given number of electrons (which could be pre-doped due to defects, gate generated or intentional doping) and a upper trion band, ET, which has a much heavier effective mass (mT=2me+mh for electron-trions), as illustrated in Fig.…”

mentioning

confidence: 99%

“…Such gain mechanisms would be extremely important for lower power, energy efficient device applications, given the current research interests of femto-or atto-joule optoelectronics (40). Excitonic related gain mechanisms for N<Nm have only been demonstrated in rare cases for conventional semiconductors, including exciton-exciton scatterings (8), localized excitons (9), localized bi-excitons (10), (free) bi-excitons (11), trions (12,13), and excitonpolariton scatterings (14). This is why such lasers have not been widely used or manufactured.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Excitonic complexes and optical gain in two-dimensional molybdenum ditelluride well below the Mott transition

et al. 2020

View full text Add to dashboard Cite

†These authors contributed equally to this work. AbstractStrong Coulomb interaction in 2D materials provides unprecedented opportunities for studying many key issues of condensed matter physics, such as co-existence and mutual conversions of excitonic complexes, fundamental optical processes associated with their conversions, and their roles in the celebrated Mott transition. Recent lasing demonstrations in 2D materials raise important questions about the existence and origin of optical gain and possible roles of excitonic complexes. While lasing occurred at extremely low densities dominated by various excitonic complexes, optical gain was observed in the only experiment at densities several orders of magnitude higher, exceeding the Mott density. Here, we report a new gain mechanism involving charged excitons or trions well below the Mott density in 2D molybdenum ditelluride. Our combined experimental and modeling study not only reveals the complex interplays of excitonic complexes well below the Mott transition, but also provides foundation for lasing at extremely low excitation levels, important for future energy efficient photonic devices.Dynamical processes of quasiparticles such as excitons and their various associated complexes (including charged excitons or trions, bi-excitons, and other highly correlated objects (1)) in solids are at the very core of fundamental condensed matter physics. The evolution of physical states from low to high carrier density involves (2-5) the insulating exciton gas, Bose-Einstein condensate (BEC) (2), co-existence of various excitonic complexes, crossover or transitions to conducting electron-hole plasmas (EHP), or electron-hole liquid (EHL) (3) through the Mott transition (MT) (4). There remain many fundamental issues to be understood associated with the evolution of such quantum quasiparticles and the related phase transitions, especially in the intermediate density regime involving highly correlated complexes. On the other hand, mutual conversions of these excitonic complexes and related phase transitions are also profoundly linked to the natures of different optical processes in semiconductors as carrier density increases (5,6). Light-semiconductor interaction thus plays important dual roles: As an information reporter, the interaction reveals the intrinsic dynamics of evolution, co-existence, and mutual conversion of various excitonic complexes in their passage towards degenerate EHP or EHL through MT, providing deep understandings of physical processes when carrier density is successively increased. At the same time, different conversion processes among various excitonic complexes provide novel absorption or emission mechanisms, forming the physical foundations for photonic functionalities including lasers, solar cells, light emitting diodes, and many other devices. While optical processes are well-understood in the two extremes: pure exciton gas and highly degenerate EHP, the intermediate stages involving various excitonic complexes are much less understood. Recent stud...

show abstract

Laser Action of Trions in a Semiconductor Quantum Well

Cited by 20 publications

References 12 publications

Probing Trions at Chemically Tailored Trapping Defects

Probing Trions at Chemically Tailored Trapping Defects

The trion: two electrons plus one hole versus one electron plus one exciton

Excitonic complexes and optical gain in two-dimensional molybdenum ditelluride well below the Mott transition

Contact Info

Product

Resources

About