Electronic States of a Shallow Hydrogenic Donor Impurity in Different Shaped Semiconductor Quantum Wells

Abstract

The shallow hydrogenic donor impurity states in square, V-shaped, and parabolic quantum wells are studied in the framework of effective-mass envelope-function theory using the plane wave basis. The first four impurity energy levels and binding energy of the ground state are more easily calculated than with the variation method. The calculation results indicate that impurity energy levels decrease with the increase of the well width and decrease quickly when the well width is small. The binding energy of the ground state increases until it reaches a maximum value, and then decreases as the well width increases. The results are meaningful and can be widely applied in the design of various optoelectronic devices.

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

“…The shape of the potential manipulates the energy levels and wave functions which can be applied to specific devices. Study of electronic as well as optical properties of NS-QW systems has been made to explore their use in novel electro-optic devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Parabolic quantum wells have been shown to provide a small leakage current for infrared detector applications [1].…”

“…The changes in the refractive index and optical absorption coefficients due to temperature, external fields and hydrostatic pressure have also been explored for a graded quantum well under intense laser field [11]. Attempts have been made to calculate impurity states for a hydrogenic donor in the square, parabolic and V-shaped QWs and it has been shown that the electron wave function strongly confines in NS potentials than in square one for higher well width [14]. Light emitting diodes are designed with asymmetric triangular multiple QW structures which have improved electroluminescence emission efficiency than the square QW [17].…”

“…We consider an Al x Ga 1−x As V-shaped double QW (D-VQW) field effect transistor (FET) structure. The V-shape well has the advantage of yielding higher confinement of wave functions as compared to square and other non-square potentials [14]. A double QW is a unique structure that can modulate the electro-optic properties through a change in the electron wave function distributions between the wells [20][21][22].…”