The electric field effects on intersubband optical absorption of Si δ-doped GaAs layer (original) (raw)
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Intersubband optical absorption of double Si δ-doped GaAs
2004
For different applied electric fields the intersubband transitions of double Si δ-doped GaAs structures are theoretically investigated for a uniform donor distribution. The electronic structure has been calculated by solving the Schrödinger and Poisson equations self-consistently. It is found that the changes of the confining potential, the subband energies and intersubband optical absorption are quite sensitive to the applied electric field. Different from the single δ-doped structure, we have seen the abrupt changing of the subband energies and the absorption coefficient whenever the applied electric field reaches two certain values. While for the (1-2) intersubband transition, the intersubband absorption spectrum shows blueshifts up to the first critical electric field value, this spectrum shows redshifts up to the second critical electric field value and shows blueshifts for higher electric fields than the second critical field values. This behavior in the intersubband transitions for different electric fields can be used in some infrared optical device applications based on the intersubband transitions of electrons.
Nonlinear intersubband optical absorption of Si δ‐doped GaAs under an electric field
physica status solidi (b), 2006
We study the nonlinear intersubband optical absorption of a single Si δ‐doped GaAs sheet placed in the middle of a GaAs quantum well and subjected to an electric field. The Schrödinger and Poisson equations are solved self‐consistently for various electric field strengths. The self‐consistent solutions provide us with the correct confining potential, the wave functions, the corresponding subband energies and the subband occupations. The nonlinear optical intersubband absorption spectra are discussed within the framework of the density matrix formulation for various electric field strengths, well widths, and sheet thicknesses in which Si atoms are distributed uniformly. We include both the depolarization and exciton shifts in calculations. The depolarization effect not only shifts the peak value but also makes the nonlinear absorption spectrum strongly asymmetric with the increasing intensity of the optical field. The blue‐shift associated with the depolarization shift is decreased w...
Nonlinear intersubband optical absorption of Si -doped GaAs under an electric field
Physica Status Solidi B-basic Solid State Physics, 2006
We study the nonlinear intersubband optical absorption of a single Si δ-doped GaAs sheet placed in the middle of a GaAs quantum well and subjected to an electric field. The Schrödinger and Poisson equations are solved self-consistently for various electric field strengths. The self-consistent solutions provide us with the correct confining potential, the wave functions, the corresponding subband energies and the subband occupations. The nonlinear optical intersubband absorption spectra are discussed within the framework of the density matrix formulation for various electric field strengths, well widths, and sheet thicknesses in which Si atoms are distributed uniformly. We include both the depolarization and exciton shifts in calculations. The depolarization effect not only shifts the peak value but also makes the nonlinear absorption spectrum strongly asymmetric with the increasing intensity of the optical field. The blue-shift associated with the depolarization shift is decreased when the intensity is increased. The absorption line shape becomes more asymmetric at smaller well widths and thicker doping layers. The electric field restores the symmetry of the absorption line shape at larger well widths and thinner doping layers, but it decreases the peak value of the line shape. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Intersubband transitions for single, double and triple Si -doped GaAs layers
Journal of Physics D: Applied Physics, 2003
The intersubband transitions in single, double and triple Si δ-doped GaAs structures are theoretically studied for different applied electric fields. Electronic properties such as the confining potential, the subband energies and the eigen envelope wave functions have been calculated by solving the Schrödinger and Poisson equations self-consistently. We have seen that the intersubband transitions are very sensitive to the type of structure and are dependent on the applied electric field. The electric field and structure dependence of the intersubband optical absorption is interesting for potential device applications in a class of photodetectors and optical modulators.
Effect of the Doping Layer Concentration on Optical Absorption in Si δ-Doped GaAs Layer
Optics and Photonics Journal, 2012
We study in this paper the intersubband optical absorption of Si- doped GaAs layer for different applied electric fields and donors concentration. The electronic structure has been calculated by solving the Schrödinger and Poisson equations self-consistently. From our results, it is clear that the subband energies and intersubband optical absorption are quite sensitive to the applied electric field. Also our results indicate that the optical absorption depends not only on the electric field but also on the donor's concentration. The results of this work should provide useful guidance for the design of optically pumped quantum well lasers and quantum well infrared photo detectors (QWIPs).
Influence of an applied electric field on the electronic properties of Si δ -doped GaAs
The European Physical Journal Applied Physics, 2003
We have theoretically studied the electronic structure of Si δ-doped GaAs inserted into an infinite quantum well as dependent on the applied electric field. For the uniform distribution we have investigated the influence of the electric field on the donor distribution thickness as different from other authors. The present method is based on a self-consistent solution of the Schrödinger and Poisson equations. From our calculations, we have seen that a high applied electric field is significantly changed the subband structure of the δ-doped GaAs and the change of the electronic properties as dependent on the applied electric field is more pronounced at wide doping thickness. The high electric fields can induce a spatial separation between confined electrons and ionized dopants in the δ-doped GaAs structure resulting in enhanced free carrier mobility in semiconductor devices. PACS. 73.90.+f Other topics in electronic structure and electrical properties of surfaces, interfaces, thin films, and low-dimensional structures (Restricted to new topics in section 73)
Electronic properties of Si δ-doped GaAs under an applied electric field
Semiconductor Science and Technology, 2001
We have theoretically investigated the electronic structure of Si δ-doped GaAs inserted into a quantum well under an applied electric field. For uniform distribution we have studied the influence of the electric field on the donor concentration. The electronic properties such as the effective potential, the density profile, the subband energies, the subband occupations and the Fermi energy level have been calculated by solving the Schrödinger and Poisson equations self-consistently. From our calculations, we have seen that the change of the electronic properties as dependent on the applied electric field is more pronounced at low doping concentration. The high electric fields can induce a spatial separation between confined electrons and ionized dopants in the δ-doped GaAs structure, resulting in enhanced free-carrier mobility in devices.
2013
In this work, we calculated the ground and first excited states of an electron confined in an asymmetric double DDQW system within a Gallium Arsenide (GaAs) matrix. The two-dimensional impurities density (N 2d) considered in our calculation are within the range of 10 12 to 10 13 cm 2. We obtain the linear and nonlinear optical properties related to intersubband transitions as a function of the spacing between-doped wells, twodimensional impurities concentrations as well as in presence of electric field. We reported results for the linear and nonlinear optical absorption coefficient and in the relative refractive index changes. Our results show that the asymmetry induced in the doubledoped well system gives rise to values that are several orders of magnitude higher in the resonant peaks intensity.
Self-consistent analysis of electric field effects on Si delta-doped GaAs
1995
Abstract. We theoretically study the subband structure of single Si &doped GaAs inserted in a quantum well and subject to an electric field applied along the growth direction. We use an efficient self-consistent procedure to solve simultaneously the Schrodinger and Poisson equations for different values of electric field and temperature. We thus find the confining po! entia!, the sibband ener9ies and their corresponding envelope functions, the subband occupations, and the oscillator strength of intersubband transfiions.
Electronic subband of single Siδ-doped GaAs structures
Superlattices and Microstructures, 2000
We have theoretically investigated the subband structure of single Si δ-doped GaAs inserted into a quantum well at T = 0 K. We will discuss the influence of the δ-doping concentration, the δ-layer thickness and diffusion of donor impurities. The spread of the impurities are taken into account in two different models: (i) a uniform distribution and (ii) a nonuniform distribution. In this paper, the nonuniform distribution is different from the Gaussian distribution use of other authors. The electronic structures have been calculated by solving the Schrödinger and Poisson equations self-consistently. We thus find the confining potential, the subband energies and their eigen envelope functions, the subband occupations and Fermi energy.