The mechanism of the near-band-gap optical transition in doped SiGe/Si quantum well is investigated

and the model of the near-band-gap optical transition originated from the statistical distribution of the impurities is suggested. The dipole matrix elements of the transition are calculated based on this model and the upper limits of the dipole matrix elements are also calculated. The mechanism of the near-band-gap optical transition in undoped SiGe/Si quantum well is also suggested that it is the collective action of the deformation wavefunction around Ge atoms. The samples of doped SiGe/Si quantum well have been grown using a molecular beam epitaxy (MBE) system and the near-band-gap optical transition from these samples was observed at low temperatures.