Room-temperature SiGe light-emitting diodes

In the present paper the electroluminescence of PIN diodes with either stra ined SiGe/Si or Ge islands in the i-region has been investigated experiment ally and by quantitative modelling. The modelling helped to improve the dio de structure. Consequently, diodes with strained Si0.80Ge0.20 could be impr oved so as to reveal emission up to room temperature, if the thickness was high enough. To overcome the thickness limitation due to plastic relaxation , we used selective epitaxy on small areas. We also present results for dio des with Ge islands in the active region. The internal quantum efficiency o f light emitting diodes with strained SiGe was at room temperature similar to 10(-4), while diodes with islands emitted ten times less light. (C) 1999 Elsevier Science B.V. AII rights reserved.