Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor

Abstract

We report electrical spin injection from a ferromagnetic metal contact into a semiconductor light emitting diode structure with an injection efficiency of 30% which persists to room temperature.The Schottky barrier formed at the Fe/AlGaAs interface provides a natural tunnel barrier for injection of spin polarized electrons under reverse bias. These carriers radiatively recombine, emitting circularly polarized light, and the quantum selection rules relating the optical and carrier spin polarizations provide a quantitative, model-independent measure of injection efficiency.This demonstrates that spin injecting contacts can be formed using a widely employed contact methodology, providing a ready pathway for the integration of spin transport into semiconductor processing technology.Revised for Applied Physics Letters 12/17/01

Surface treatments and magnetic properties of Ga1−xMnxAs thin films

“…It is well known that the Fe/GaAs(1 0 0) interface has a great relevance due to the lack of any magnetically dead layer at the interface [15], and the possibility of realizing efficient spin injection in GaAs [16]. It would be interesting to study the analogous Fe/(Ga,Mn)As, because the behaviour of this hole-doped DMS upon electron spin injection is absolutely unknown.…”

Ballistic hole magnetic microscopy

“…Moreover, if holes can cross the Schottky barrier without losing spin information, the method may find an important application in spin injection of holes into a semiconductor, complementary to spin injection of electrons into the conduction band of n-type semiconductors. 12,13 The principle of the technique is illustrated in Fig. 1.…”

Spin injection from Co2MnGa into an InGaAs quantum well

“…This type of spin LED design is based on a n-Al 0.33 Ga 0.67 As Schottky LED structures which were used to successfully demonstrate spin injection from Fe into GaAs/ AlGaAs QWs. 10 Further, the oblique Hanle geometry can be used to estimate the effective spin lifetime in the QW. 11 The structure comprises a GaAs based LED structure with a surface Schottky barrier onto which a ferromagnetic metal layer is grown.…”