Interference of Light- and Heavy-Hole Contributions to the Electroreflectance Spectrum of Germanium

Abstract

starting from a localized picture.^ In this model the metallic phase is composed of a degenerate gas of n-and/)-type small polarons. The M-I transition occurs when the Mott-Hubbard correlation gap exceeds twice the polaron binding energy.It is clear that further theoretical and experimental work is needed to elucidate the detailed nature of the transition. A complete report of the results will be published elsewhere.We thank P.

Stark effect and Franz-Keldysh effect of a quantum wire realized by conjugated polymer chains of a diacetylene 3NPh2

“…7. Although expected for the Franz-Keldysh e¤ect 24 it has been observed at similar …elds only in semiconductors with small reduced mass like Ge, 25 GaAs 26 and InGaAs 27 but also in fully polymerized DCH 9 and on blue chains in 3BCMU and 4BCMU monomer single crystals. 10 Fieldbroadening leads to a redshift of the …rst peak at 3.10 eV and a blueshift of all peaks above 3.15 eV.…”

Excitonic electroabsorption spectra and Franz-Keldysh effect ofIn0.53Ga0.47AsJaeger1, Weiser2 1998Phys. Rev. B261130View full textAdd to dashboardCite

“…The stronger heavy-hole transitions dominate the general shape of the spectrum and the position of the peaks while light-hole transitions cause the beat of the peak amplitudes first observed at the gap of Ge. 27 Because of their smaller reduced mass light holes scale to a larger electro-optic energy and yield an independent set of smaller amplitude and different period. At fields above 20 kV/cm the oscillations from the band gap reach the gap of the split-off valence band where another set of oscillations is observed and above 35 kV/cm oscillations stretch over 0.5 eV up to the gap of the InP substrate.…”

Parallel Nature of theΛ1−Λ3Energy Bands in Germanium

“…Because the A x and A 3 energy bands are so nearly parallel over a large part of the BZ, 5 it seems more reasonable to suggest that the observed spectra may best be described by the twodimensional critical-point theory. 6 The present experiments were performed at room temperature using the electrolyte technique, 7 We report that the 2-eV electroreflectance structures in germanium can be represented by a two-dimensional critical line which contains the L point and extends over approximately 80% of the distance from L to F. which we were able to monitor under actual experimental conditions, is necessary to obtain data which can be interpreted. Experimental data which do not satisfy this criterion cannot be used to validate theoretical models.…”

“…In real materials the hole can also tunnel directly to a second-neighbor metal-ion site via hybridization with the nonmetal orbitals, thus avoiding the spin restriction studied above. 7 This might also lead to AF exciton line shapes closer to a 6 function. Direct measurements, perhaps comparing Raman scattering from exciton states above and below T N in order to eliminate backgrounds, should help clarify which of the mechanisms dominates hole propagation in real materials.…”