Anomalous electron spin splitting in InAs pumped by injection

The electroluminescence and photoluminescence of bulk n-InAs with a high concentration of donors (N _d ≈ 5 × 10¹⁶ cm^?3) is studied experimentally in magnetic field in the Faraday layout of the experiment. Under the conditions of electrical injection, the photon energy corresponding to the electroluminescence peak exceeds the energy band gap E _g. When a magnetic field is applied, the energy of the peak becomes lower than E _g, and the peak splits into two circular-polarized components. The splitting depends on the injection current. In moderate magnetic fields (about 2 T), the splitting can be much more profound than the calculated splitting corresponding to the well-known g factor of electrons in InAs. The effect is attributed to different degrees of magnetic freezing-out of electrons with different spin orientation. The maximum in the dependence of the degree of polarization of photoluminescence on the magnetic field and the behavior of the photoluminescence line width support the model suggested.