ABSORPTION AND RECOMBINATION IN P-TYPE SIGE QUANTUM-WELL STRUCTURES

We consider the possibility of obtaining normal incident absorption in the 10-15 mum range, using strained p-type SiGe quantum well structur es using a full-scale relativistic pseudo-potential method. We predict the magnitude and the position of the peak absorption response and de termine the microscopic (band structure) origin of the peaks. We show that major contributions to the absorption occur away from the centre of the first Brillouin zone, and thus the energy of the peak response cannot be accurately predicted by simple particle-in-a-box models. Als o we discuss the possibilities of engineering the band structures of t hese systems so as to minimize non-radiative (Auger) recombination. Co mparisons of the parallel incidence absorption response calculated by our method with recent experimental results are presented.