Scrutiny of Injected Electron Current Polarization Effect on the Threshold Current Density Reduction in QW Spin-Lasers

Abstract

One of the mechanisms for threshold current density reduction is using spin polarized carriers generated by electrical spin injection. Electrical spin injection is spin-polarized carrier injection by using a magnetic contact. In this paper, we have solved numerically rate equations governing on semiconductor spin un-polarized and polarized laser with - based quantum well active region in which Schottky tunnel barrier treat as the spin injector. For the first time, we demonstrate simultaneously effect of normalized spin relaxation rate and injected current polarization on threshold current density reduction related to two form of spontaneous recombination. According to our result threshold current density reduction increases by simultaneously normalized spin relaxation rate reduction and increasing of injected current polarization. Maximum obtained threshold current density reduction values for linear and quadratic spontaneous recombination is 0.07 and 0.31. Moreover, we compute and compare the effect of value of injected electron current polarization on normalized spin-filtering interval for two types of recombination. Maximum obtained normalized spin-filtering interval values for linear and quadratic spontaneous recombination is 1.2 and 1.36. Finally we calculate spin-up optical gain and from this we obtained the conditions for achieving optimum optical gain. Maximum obtained spin-up optical gain valueis17.36.