CLEAVAGE LUMINESCENCE FROM INP, GE AND GEXSI1-X

The luminescences occurring on cleaving InP, Ge, and three different c ompositions of GexSi1-x have been measured, and found to show a common characteristic in that there are at least two types of emissions in d ifferent wavelength regions. One type appears from cleavages in vacuum only and has relatively long durations in the cases of the elemental semiconductors. The origin is recombination of cleavage-excited electr ons across the bulk band gap. There is evidence that the excited elect rons are in a non-equilibrium (''hot'') distribution. The other type o f luminescence appears also in air, and has short (20 mus or less) dur ations for all of the materials. This radiation is ascribed to recombi nation at surface defects, including vacancies.