Theory of photoluminescence in semiconductors

Hannewald, Karsten; Glutsch, S.; Bechstedt, F.

doi:10.1103/physrevb.62.4519

Cited by 46 publications

(44 citation statements)

References 20 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A quantitative simulation of the optical properties of photo-excited semiconductors with full consideration of microscopic interactions, spin-dependent effects of band-gap renormalization, taking into account the transitions from both heavy-hole and light-hole bands is a self-consistent problem 23 beyond the scope of this paper. However, a qualitative simulation of the spectral behavior of the populationinduced and splitting-induced contributions to the photoinduced magneto-optical Kerr effect can be achieved by solving the optical Bloch equations separately for phasespace filling ͑i͒ and spin-dependent band-gap renormalization effects ͑ii͒ within the approximation of an ensemble of two-level systems, which in principle only applies to excitonic transitions.…”

Section: ͑7͒mentioning

confidence: 99%

“…The phase-space filling contribution brings information about the time-dependent redistribution of carriers due to carriercarrier and carrier-LO phonon interactions. 22,23 ͑ii͒ A term accounting for the energy renormalization or self-energy terms, which describe the changes in one-particle dispersion relations due to the Coulomb interaction. In the simplest, mean-field approximation, the self-energies ⌺ s (k) and ⌺ j (k) are given by:…”

Section: ͑2͒mentioning

confidence: 99%

See 1 more Smart Citation

Room-temperature ultrafast carrier and spin dynamics in GaAs probed by the photoinduced magneto-optical Kerr effect

et al. 2001

View full text Add to dashboard Cite

The picosecond and subpicosecond dynamics of spins in intrinsic and n-doped GaAs is investigated at room temperature using the time-resolved, pump and probe, photoinduced, near-resonant magneto-optical Kerr effect between 1.44 and 1.63 eV. Three components with different temporal and spectral behavior are distinguished in both Kerr rotation and ellipticity, and their origin is discussed in relation with theoretical predictions and simulations. Two contributions are attributed to the splitting of the spin sublevels. The first one, present only as long as pump and probe pulses coincide in time, is a coherent response accounted for in terms of the optical Stark effect, whereas the longer decay of the second one, up to 35 ps, is attributed to electron spin relaxation. The third component is assumed to arise from the difference in population of the photoexcited states and decays within a time smaller than the pulse duration, which is attributed to the energy relaxation of electrons towards the bottom of the conduction band through carrier-carrier and carrier-phonon scattering.

show abstract

Section: ͑7͒mentioning

confidence: 99%

Section: ͑2͒mentioning

confidence: 99%

Room-temperature ultrafast carrier and spin dynamics in GaAs probed by the photoinduced magneto-optical Kerr effect

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Although this proposed interpretation is currently largely questioned (see for example Hannewald and Glutsch et al [17]), the dominance of the excitonic transition at the shortest time has not received a sensible explanation yet.…”

mentioning

confidence: 99%

Determination of the Exciton Formation in Quantum Wells from Time-Resolved Interband Luminescence

et al. 2004

View full text Add to dashboard Cite

We present the results of a detailed time resolved luminescence study carried out on a very high quality InGaAs quantum well sample where the contributions at the energy of the exciton and at the band edge can be clearly separated. We perform this experiment with a spectral resolution and a sensitivity of the set-up allowing to keep the observation of these two separate contributions over a broad range of times and densities. This allows us to directly evidence the exciton formation time, which depends on the density as expected from theory. We also evidence the dominant contribution of a minority of excitons to the luminescence signal, and the absence of thermodynamical equilibrium at low densities.PACS numbers: 71.35.Cc,71.35.Ee,73.21.Fg,78.47.+p,78.67.De Excitons in quantum wells form quite an appealing quasiparticle showing a large range of optical properties that have proven at the same time technologically useful, and physically interesting [1]. A large part of this interest is linked with the appearance of excitonic resonances in absorption up to room temperature. It is also well known, since the seminal work of Weisbuch et al [2], that free excitons appear to dominate the luminescence response of semiconductor quantum wells at low temperatures. Part of the origin of this effect lies in the breakdown of the translational symmetry which brings a very efficient recombination channel to free excitons in quantum wells [3,4].Interestingly, in the low density regime, time resolved luminescence (TR-PL) in quantum wells is observed to be always dominated by light coming at the exciton energy, even under non resonant excitation. The observations of this dominant contribution are so numerous that only a very partial list of references may be given here [5,6,7,8,9] (in order to be specific, we only consider here the case of quantum wells grown on GaAs substrates). A double question has then been debated for more than 10 years in the literature: first how do free electron hole pairs bind into excitons and second does indeed the luminescence at very short time proceed from bound excitons. A brief survey of the literature allows to find that experimentalists have reported formation times ranging from less than 10 ps up to about 1 ns [7,8,9, 10] and theoretical values range from 100 ps [11,12,13] to over 20 ns [14]. Clearly, the origin of this spreading in the reported values lies in the poor sensitivity of the experiments used in general to probe the exciton formation process, except for the case of the recent terahertz absorption experiments [10]. On the theoretical side, binding of an electron hole pair into an exciton requires, at low temperatures, the emission of an acoustic phonon, which brings long formation time due to the small coupling of acoustic phonons to excitons.The long formation time of excitons, together with the observation of luminescence at the exciton energy at the shortest times [7,15] led Kira et al [16] to introduce the idea that a free electron hole plasma, properly including Coulomb correla...

show abstract

“…This part of the theory is also useful to calculate photoluminescence spectra. 55 From the lesser and greater eh propagators we construct the (self-energy) vertex and subsequently the spectral function, see Section V B. Taking into account the quasi-stationarity of the system we finally obtain a simple and intuitive expression for the (dressed) lesser Green's function.…”

Section: Introductionmentioning

confidence: 99%

First-principles approach to excitons in time-resolved and angle-resolved photoemission spectra

et al. 2016

View full text Add to dashboard Cite

We show that any quasi-particle or GW approximation to the self-energy does not capture excitonic features in time-resolved (TR) photoemission spectroscopy. In this work we put forward a first-principles approach and propose a feasible diagrammatic approximation to solve this problem. We also derive an alternative formula for the TR photocurrent which involves a single time-integral of the lesser Green's function. The diagrammatic approximation applies to the relaxed regime characterized by the presence of quasi-stationary excitons and vanishing polarization. The main distinctive feature of the theory is that the diagrams must be evaluated using excited Green's functions. As this is not standard the analytic derivation is presented in detail. The final result is an expression for the lesser Green's function in terms of quantities that can all be calculated ab initio. The validity of the proposed theory is illustrated in a one-dimensional model system with a direct gap. We discuss possible scenarios and highlight some universal features of the exciton peaks. Our results indicate that the exciton dispersion can be observed in TR and angle-resolved photoemission.

show abstract

Theory of photoluminescence in semiconductors

Cited by 46 publications

References 20 publications

Room-temperature ultrafast carrier and spin dynamics in GaAs probed by the photoinduced magneto-optical Kerr effect

Room-temperature ultrafast carrier and spin dynamics in GaAs probed by the photoinduced magneto-optical Kerr effect

Determination of the Exciton Formation in Quantum Wells from Time-Resolved Interband Luminescence

First-principles approach to excitons in time-resolved and angle-resolved photoemission spectra

Contact Info

Product

Resources

About