Electronic states in diffused quantum wells

Vlaev, S.; Contreras-Solorio, D. A.

doi:10.1063/1.365750

Cited by 18 publications

(13 citation statements)

References 16 publications

(39 reference statements)

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“…We shall use a method recently developed in [22] to treat planar heterostructures with inhomogeneities in the growth direction. This method was successfully applied to discuss the optical transitions in diffused quantum wells [23] and the Stark shifts in rectangular and graded composition quantum wells [24].…”

Section: Introductionmentioning

confidence: 99%

Stark effect in diffused quantum wells

Vlaev

Miteva

Contreras-Solorio

et al. 1999

Superlattices and Microstructures

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Section: Introductionmentioning

confidence: 99%

Stark effect in diffused quantum wells

Vlaev

Miteva

Contreras-Solorio

et al. 1999

Superlattices and Microstructures

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“…The Fourier implementation of the heterostructure bandstructure models based on effective mass, k · p or hybrid methods is similar to the models developed here, with the appropriate substitution of the real-space derivatives. The tight-binding model is usually less accurate than k · p methods for determining the optical properties of a semiconductor, but it has also been used to determine the bandstructure of a single disordered quantum well [36].…”

Section: -Band K · P Representationmentioning

confidence: 99%

Electronic bandstructure of disordered superlattices

Hutchings

1999

Superlattices and Microstructures

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“…The size of the inhomogeneous slab is 300 monolayers. The Green function of the external barriers is calculated from the transfer matrix in the usual way, and the Green function of the δ-doped well region is calculated by means of the algorithm already established and used to study other quantum structures [25,26]. The calculations are performed at the center of the twodimensional Brillouin zone (2DBZ) for the (001) growth direction.…”

mentioning

confidence: 99%

“…The sp 3 s * spin dependent semi-empirical tight-binding model and the surface Green function matching method are applied (see [25,26] and the references therein). The δ-doped well is divided into three regions, namely, the external homogeneous GaAs barriers and the internal inhomogeneous (δ-doped) well region.…”

mentioning

confidence: 99%

Resonant states in n ‐type δ‐doped GaAs quantum wells

Vlaev

Rodrı́guez-Vargas

Gaggero‐Sager

2005

phys. stat. sol. (c)

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PACS 71.15.Dx, 71.15.Qe, 73.21.Fg We calculate the electron structure of δ-doped GaAs quantum wells within a realistic sp 3 s* tight-binding formalism, including spin. The results reveal the existence of a series of many quasi-bound states with a very strong spatial and energetic localization. For a donor impurity concentration of n 2D =1×10 13 cm -2 the full width at half maxima (FWHM) of the first quasi-bound state is 1.5×10-3 meV and the corresponding mean-life time is about 4 ns. This value is 10 3 times greater that the mean lifetime reported for Bragg's reflectors based on quantum wells. We find many similar features of the symmetry, spatial and energetic characteristics between quasi-bound and bound states.The study of the bound states in semiconductor quantum systems is very old and extensive. Nevertheless, the study of the quasi-bound states is a new one. The eigen-values change significantly from one system to another, but the shape of the eigen-functions is similar. The nature of the quasi-bound states can be different. There are quasi-bond states formed by the presence of two thin barriers [1, 2], a barrier [3,4], a quantum well with a finite superlattice [5] or only a quantum well [6]. Optical transitions between the conduction band states arising from spatial confinement in quantum Heteroestructuras have been observed for the first time by West and Eglash [7]. These transitions having enhanced intersubband oscillator strengths can be used for novel electronic and optical device applications. The technology of quantum well infrared photodetectors (QWIP's), an intersubband device, has progressed as a rapid pace since the demonstration of the first GaAs/AlGaAs QWIP, which employed a photo-excited tunnelling intersubband transition [8]. Voltage-tuneable multi-wavelength QWIP's [9] and QWIP's with narrow-band IR detection [10] have also demonstrated their advantages in the practical applications. Superlattice modulators exploiting the large linear Stark shift in intersubband transitions in quantum wells [11] and tunnellingelectron-assisted modulators [12] have been explored due to their potentially ultra-fast operation. Intersubband lasers emitters have been proposed and fabricated [13]. Quantum cascade electroluminiscent devices have been recently reported [14][15][16] The so called quasi-bound states appear in the continuum spectrum for some kind of potentials [17]. The existence of quasi-bound states has been reported in [18][19][20][21][22][23][24]. These states can be exploited in photo-detectors, modulators and switching devices.As we can see from the literature, the above barrier states are normally studied for rectangular potential profiles. In the present paper we study quasi-bound states in δ-doped GaAs quantum wells. The calculations are performed within the realistic sp 3 s * semi-empirical tight-binding model including spin.

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Electronic states in diffused quantum wells

Cited by 18 publications

References 16 publications

Stark effect in diffused quantum wells

Stark effect in diffused quantum wells

Electronic bandstructure of disordered superlattices

Resonant states in n ‐type δ‐doped GaAs quantum wells

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