H. Akbas

Electric field effect on the binding energy of a hydrogenic impurity in coaxial GaAs/Al xGa1 − x As quantum well-wires

The ground state binding energy of a hydrogenic impurity in a coaxial cylindirical quantum well wire system subjected to an external electric field applied perpendicular to the symmetry axis of the wire system is studied within a variational scheme. Binding energy calculations were performed as functions of the inner barrier thickness and the electric field for two different impurity positions. The main result is that a sharp decrease in the binding energy, which may be important in device applications, occurs in certain conditions.

Shallow Donors in a Quantum Well Wire: Electric Field and Geometrical Effects

Subband and shallow donor binding energies are calculated. The emphasis is given on the electric field effects for wires of different shapes. It is shown that the donor binding energy is sensitive to the interplay of the electric field and geometrical effects.

Acceptor 1s—2p± Transitions in GaAs/Ga0.7Al0.3As Quantum Wells: Effects of Spatially Dependent Screening under Electric and Magnetic Fields

The valence subband energies in the presence of an electric-field are calculated using the fourth-order Runge-Kutta method. The 1s- and 2p±-like acceptor states in the presence of a magnetic field are then calculated variationally. The effects of the spatially dependent screening function e(r) on the calculation of the transition energies are specifically investigated. The use of a constant e n is shown to yield better agreement with experimental results.