Lifetime Of Electron Tunneling Through Semiconductor Hereostructure

In this paper, the escape of electron from a quantum well is investigated by using the Projection Green’s Function method (PGF) and recursive method under the effective mass approximation. Furthermore, this method has been developed to study the problem of spin-polarized electron tunneling with taking account of the k3Dresselhaus spin orbit coupling effect. The lifetime and spin polarization efficiency have been discussed in detailed.Firstly, the combination of PGF and recursive method was used to solve the shrodinger equation. The escape time from GaAs/Al0.3Gao0.7As multiple quantum well structure has been calculated and analyzed. We have investigated the effect of the structure parameters on tunneling escape time. The results show that the tunneling lifetime would increase rapidly with changing of the first barrier thickness. However, the effect of changing the second barrier thickness on the tunneling lifetime is very small (only a few percent). Effect of changing the first well and second well on the electron tunneling lifetime is opposite.Additionally, in order to study the effect of spin polarization on tunneling lifetime and polarization efficiency, we have developed the Projection Green’s Function method by taking account of considering k3Dresselhaus spin orbit coupling in double heterostructure GaAs/Al0.3Ga0.7As quantum well system. It is found that the splitting of the electron tunneling lifetime has been obtained due to the k3Dresselhaus spin orbit coupling. The resonant energy level of the spin-down electron moved toward the lower energy region, and the energy level of spin-up electron moved towards higher energy region. The lifetime of different spin-polarized electron and spin polarization are affected by the width of well and the barrier of thickness.