Enhancement of high-temperature photoluminescence in strained Si1−xGex/Si heterostructures by surface passivation

The photoluminescence from strained Si1−xGex alloy quantum wells on Si(100) has been measured from 6 to 300 K. It is shown that the high-temperature photoluminescence of Si1−xGex quantum wells can be increased by over an order of magnitude by passivation of the top silicon surface. Through experiments and a model, it is clearly demonstrated that the decay of the Si1−xGex photoluminescence at high temperature is controlled by surface recombination, not by an intrinsic property of Si1−xGex. By applying proper conditions, nearly constant Si1−xGex photoluminescence can be achieved from 77 to 250 K.