Abstract:We compare the transport properties for triangular, parabolic and cubic quantum wells. We calculate the transport mobility for electrons belonging to the different subbands. We obtain the energy spacing between first and second subbands from the electron sheet density and compare results for different potential profiles. We find that experimental results are in quantitative agreements with our calculations.
“…The electron mobility µ is demonstrated as a function of 2D‐electron density in GaAs/Al x Ga 1 −x As QWs by considering triangular, parabolic, and cubic potential structures . It has been shown that in a wide well structure the background impurity limits the mobility . Although a great deal of efforts has been made to investigate the optical properties of the non‐square potential well structures, very few attempts have been made to study the electron transport properties of these structures.…”
Section: Introductionmentioning
confidence: 99%
“…In recent years, there is considerable interest in the study of semiconductor quantum well (QW) structures having different shapes of confinement potentials, viz., square, parabolic, graded, V‐shaped, inverse parabolic, triangular, etc., because of their applications in devices . The change in the potential profile of a quantum well affects the subband energy states.…”
Section: Introductionmentioning
confidence: 99%
“…The theoretical study of the optical properties, such as laser dressing effects, polarizability, optical absorption coefficient has been made by considering GaAs/Al x Ga 1 −x As based QWs with different shapes of potentials. The electron mobility µ is demonstrated as a function of 2D‐electron density in GaAs/Al x Ga 1 −x As QWs by considering triangular, parabolic, and cubic potential structures . It has been shown that in a wide well structure the background impurity limits the mobility .…”
Herein, it is shown that the oscillation of low temperature electron mobility μ can be obtained as a function of external electric field F in AlxGa1−xAs based V‐shaped double quantum well (VQW) structure. The oscillation of μ can be enhanced by increasing the well width and barrier width as well as decreasing the doping concentration and height of the V‐shaped potential. The mobility due to the ionized impurity (II‐) scattering μII is responsible for the oscillation of μ through intersubband effects within double subband occupancy. On the other hand, the mobility due to the alloy disorder (AD‐) scattering, μAD, which shows almost a flat‐like character, governs the overall magnitude of μ. It is further gratifying to show that the drop in μ at the transition from single to double subband occupancy minimizes and even alters to a rise in μ by varying the AD‐scattering potential through the structure parameters of the VQW. These results can be utilized to analyze the non‐square quantum well based field effect transistors.
“…The electron mobility µ is demonstrated as a function of 2D‐electron density in GaAs/Al x Ga 1 −x As QWs by considering triangular, parabolic, and cubic potential structures . It has been shown that in a wide well structure the background impurity limits the mobility . Although a great deal of efforts has been made to investigate the optical properties of the non‐square potential well structures, very few attempts have been made to study the electron transport properties of these structures.…”
Section: Introductionmentioning
confidence: 99%
“…In recent years, there is considerable interest in the study of semiconductor quantum well (QW) structures having different shapes of confinement potentials, viz., square, parabolic, graded, V‐shaped, inverse parabolic, triangular, etc., because of their applications in devices . The change in the potential profile of a quantum well affects the subband energy states.…”
Section: Introductionmentioning
confidence: 99%
“…The theoretical study of the optical properties, such as laser dressing effects, polarizability, optical absorption coefficient has been made by considering GaAs/Al x Ga 1 −x As based QWs with different shapes of potentials. The electron mobility µ is demonstrated as a function of 2D‐electron density in GaAs/Al x Ga 1 −x As QWs by considering triangular, parabolic, and cubic potential structures . It has been shown that in a wide well structure the background impurity limits the mobility .…”
Herein, it is shown that the oscillation of low temperature electron mobility μ can be obtained as a function of external electric field F in AlxGa1−xAs based V‐shaped double quantum well (VQW) structure. The oscillation of μ can be enhanced by increasing the well width and barrier width as well as decreasing the doping concentration and height of the V‐shaped potential. The mobility due to the ionized impurity (II‐) scattering μII is responsible for the oscillation of μ through intersubband effects within double subband occupancy. On the other hand, the mobility due to the alloy disorder (AD‐) scattering, μAD, which shows almost a flat‐like character, governs the overall magnitude of μ. It is further gratifying to show that the drop in μ at the transition from single to double subband occupancy minimizes and even alters to a rise in μ by varying the AD‐scattering potential through the structure parameters of the VQW. These results can be utilized to analyze the non‐square quantum well based field effect transistors.
“…The specific nature of these potentials also causes dramatic change in the electrical and optical properties of the system [4,7,9]. The potentials like parabolic [1][2][3][4], triangular [5][6][7][8][9], graded [10][11][12], V-shaped [13][14][15], cubic [14,15], inverse-parabolic [16][17][18], semi-parabolic [19,20], inverse V-shaped [21], semi V-shaped [22], square-parabolic [23], Gaussian [24] etc are the examples of such systems. Light emitting diodes based on triangular-shaped QWs have more internal quantum efficiency compared to that of rectangular ones [6].…”
Section: Introductionmentioning
confidence: 99%
“…Radu et al have calculated laser-dressed states of electrons in graded QWs [10]. Magnetotransport properties of non-square QWs are studied by Mamani et al [15]. Ozturk et al have compared the linear optical absorption coefficients of parabolic with inverse parabolic QWs through the dipole moment matrix elements [16].…”
The importance of non-square quantum well potential profile on the electron mobility µ of coupled double quantum well based modulation doped field effect transistor (MOD-FET) structure is studied. We consider non-square cubic structure potential, V DS (z) α z 3 , where z denotes the position coordinate from the center of the well. The cubic double quantum well (CD-QW) is made of Al x Ga 1−x As alloy in which both the side barriers are δ-doped with Si. We consider ionized impurity (imp-) and alloy disorder (al-) scatterings for the calculation of µ. We investigate the variation of the structure parameters, such as well width, barrier width, alloy concentration and doping concentration on µ. The nonlinear behavior of µ can be achieved by properly tuning the structure parameters, mostly controlled by imp-scatterings. We show that under suitable structure parameters µ is enhanced in CD-QW as compared to that of a conventional SD-QW structure. Our analysis will help improve the channel conductivity in QW based MOD-FETs.
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