High temperature (77-300 K) photo- and electroluminescence in Si/Si1-xGex heterostructures

The photo- and electro-luminescence of strained Si1-xGex/Si heterostructures on Si(100) substrates from 77 K to 300 K has been investigated both experimentally and by quantitative modelling. The key experimental features are very broad linewidths and an exponential drop in the luminescence at high temperatures, with a larger Ge fraction corresponding to a higher temperature before the drop begins. These phenomena were accurately explained by an electron-hole plasma from high carrier densities in the quantum well and by an excessively low effective lifetime in the silicon cladding region.