Free Carrier Compression and Galvanomagnetic Luminescence of Germanium at High Lorentz Fields

Abstract

AbstractA local variation in carrier concentration occurs in intrinsic semiconductors in the presence of crossed electric and magnetic fields which leads partly to an enhancement (“compression”) and partly to a depletion. In connection with these displacements from thermal equilibrium luminescent radiation can be observed which, when related to the thermal radiation under equilibrium conditions, is positive in enhanced and negative in depleted regions. The luminescent radiation spectrum in the region of the fundamental absorption edge is directly related to the free carrier concentration profile in the sample. The report deals with theoretical and experimental results obtained with germanium exposed to Lorentz field strengths of up to 20000 TV/m (or B ≦ 10 T) at 400 K. Non‐linear surface recombination must thereby be allowed for. The corresponding semiconductor parameters are given. The modulated galvanomagnetic luminescence exhibits the expected antiphase component at longer wavelengths, corresponding to an increase in the separation of the quasi fermi level from the band edges for constant lattice and electron temperatures.