Current-induced light emission by narrow-gap semiconductors in a magnetic field
Morimoto and Chiba (1991 J. Phys. Soc. Japan. 60, 2446) have observed a threshold behaviour of current-induced interband light emission from n-InSb samples in a magnetic field, attributing this to the onset of stimulated emission. We show that their experimental results can be explained quite satisfactorily by the combined effect of sample heating by current and surface accumulation of minority carriers under the action of the Lorentz force. We also derive for intrinsic narrow-gap semiconductors the condition for achieving population inversion within a narrow accumulation layer by passing current in a transverse magnetic field.