Oscillation of Electron Mobility in V‐Shaped Double Quantum Well Structure Under Applied Electric Field

Abstract

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.

Asymmetric doping induced nonlinear electron mobility in double V-shaped quantum well based FET structure under external electric field

“…It would be interesting to compare our results of oscillatory μ as a function of F (figure 2) with that of a symmetrically barrier-doped DQW structure [34]. We note that in the case of structural and doping symmetry, the DQW is potentially symmetric at F=0.…”

“…By applying F towards the surface (say, along the positive z-axis) and substrate (along negative z-axis), the potential tilts equally in the respective directions through V F (z). As a result, there occurs identical nonlinear variation of μ with F in both the directions, thereby exhibiting a symmetric pattern about F=0 with a dip in μ near the RSS [34]. Whereas in the present case, because of single side doping, the asymmetry in the potential of the DQW is compensated by varying the external electric field F along the positive z-axis and at F=9.8 kV cm −1 RSS occurs leading to an asymmetric oscillatory variation of μ.…”

Effect of structure parameters on electron mobility in asymmetric V-shaped double quantum well structure

“…Also, the introduction of a thin barrier layer between two VQW structures makes a V-shaped double quantum well (VDQW) structure. In addition to the confinement effect, the coupling of subband wave functions and splitting of energy levels give interesting phenomena like the resonance of subband states which modify the transport as well as optical properties of VDQW based devices [16][17][18][19][20][21][22][23][24]. Numerous studies have been made to alter the optical characteristics of single and double QW structures with V-shaped, semi-V-shaped, and inverse V-shaped shapes [7,[25][26][27][28][29][30][31][32][33].…”

Investigation on Nonlinear Optical Properties of Symmetric and Asymmetric Double V-Shaped Potential Wells with Structural Parameters and External Electromagnetic Fields

“…Such as other types of non-square wells, V-shaped QWs offer distinctive electronic and optical characteristic with stronger quantum confinement potentials compared to square type wells [23,24]. Furthermore, the feasible asymmetry tailoring via structure parameters made double V-shaped quantum wells (DVQWs) the subjects of some studies as given follows: The tunable nonlinear electron mobility by varying well width, barrier width, doping concentration and potential height of V-shaped double well in the presence of external electric field is examined in [24,25]. In these studies, the possible usage of that QW in mobility adjustment for fine-tuning of channel conductivity is illustrated.…”