Doping-induced bandgap narrowing in Si rich n- and p-type Si1-xGex

• The shifts of the fundamental and optical bandgap energies as functions of dopant concentration in heavily n-type and p-type doped Si1-xGex (x less than or equal to 0.3) have been investigated theoretically. The band structure of the intrinsic crystal was described by the k . p-perturbation method, where the Kohn-Luttinger parameters were determined from a first-principles and full-potential band-structure calculation. The doping-induced effects on the bandgap were thereafter calculated using a zero-temperature Green function formalism within the random phase approximation and with a local field correction of Hubbard. We found only small effects on the bandgap energies due to variation of composition x. The calculated bandgap narrowing of Si and of Si0.82Ge0.18 were found to be in good agreement with photoluminescence measurements.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

heavily doped silicon

bicmos technology

electron-gas

semiconductors

ge

photoluminescence

layers

alloys

energy

shifts

Condensed matter physics

Semiconductor physics

Defects and diffusion

Electronic structure

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)