Room-temperature 1.3- and 1.5- mu m electroluminescence from Si/Si/sub 1-x/Ge/sub x/ quantum wells

The authors report the first room-temperature electroluminescence (EL) from Si/SiGe quantum-well structures with peak emissions at 1.3 and 1.5 mu m. The peak intensities are relatively insensitive to temperature from 77 to 300 K. The LED (light emitting diode) has a p-i-n structure with an active intrinsic region which consists of ten 60-AA Si/sub 0.65/Ge/sub 0.35/ quantum wells for the 1.3- mu m device and a single 13-AA Ge layer for the 1.5- mu m device. Well-resolved low-temperature (4 K) photoluminescence (PL) shows that the 1.3- mu m luminescence is from the no-phonon band-edge exciton recombination in the Si/sub 0.65/Ge/sub 0.35/ quantum wells. The same physical mechanism is responsible for room-temperature 1.3- mu m luminescence. The internal quantum efficiency of the 1.3- mu m LED diode is estimated to have a lower limit of 2*10/sup -4/.