RELAXATION OF AUGER-EXCITED CARRIERS IN SILICON*

The near-2-Eg luminescence of highly pure silicon has been studied at liquid helium temperature under high-excitation condition. Besides the luminescence line at 2.27 eV arising from two-electron band-to-band transitions in the electron—hole drops (EHD), a broad, slightly structured spectrum at energies lower than 2E~was found. From the intensity and from the shape of this spectrum, it is concluded that it must be referred to the radiative recombi-nation of hot carriersgenerated by Auger recombination in the EHD. Good agreement is found with a theoretical calculation. LUMINESCENCE studies in the hot electron region silicon near 1 eV above the band edge could be detected havebeen done by several authors. Commonly hot elec- by measuring the luminescence arising from the trons were generatedby high electric fields in the ava- radiative recombination of these carrierswith therm-lanche breakdown of reverse-biased diode structures.14 alized ones with opposite sign in the EHD. The so achieved broad and nearly unstructured spectra are quite well understood ~ and can be described by The experimental arrangement, in which these a constant energetic distribution of hot carriers ruled measurements were done, consisted ofa liquid heliu