Photoluminescence from short-period strained-layer superlattices of (Si 6Ge 4) p after hydrogen passivation

Abstract

Low temperature photoluminescence from different short-period (Si m Ge n ) p superlattices ( m = 6, n = 4, p = 60, 100) is determined before and after various hydrogen plasma treatments. The original samples exhibit well-known broad luminescence features with maxima at about 0.8 eV and display no excitonic recombinations from the superlattice. After hydrogen plasma treatment, the total luminescence intensity increase, and new luminescence bands appear. In particular, in samples with minor quality, luminescence from transition metals is identified. In our best samples, however, we find evidence for an excitonic recombination in the superlattice.