Hot Carriers in Microplasmas and their Radiation in Germanium and Silicon

On the basis of Chambers' equation, assuming the mean free path of carriers to be independent of energy, the form of the distribution function for high electric fields is obtained. Using the distribution function, the spectrum of light emitted from reverse biased junctions in Ge and Si is computed. It is assumed that this emitted light origins from bremsstrahlung of “hot” carriers in the Coulomb field of charged centres. Good conformity of the theoretical curves with the experimental results of C HYNOWETH and G UMMEL , C HYNOWETH and M C K AY , D AVIES and S TORM is obtained for both germanium and silicon junctions. This agreement is best for field intensities of the order of 10 5 to 10 6 V/cm (calculated for an assumed mean free path of 200 Å) and lattice temperatures giving microplasmas in the region 350 to 700 °K.