BAND-GAP NARROWING DETERMINATION BY PHOTOLUMINESCENCE ON STRAINED B-DOPED SI0.82GE0.18 LAYERS GROWN ON SI

This work reports on photoluminescence (PL) characterization of heavy boron-dope SiGe(p+)/Si(p) heterostructures and Si(p+)/Si(p) pseudohete rostructures grown by rapid thermal chemical vapor deposition. For the pseudoheterostructures, the band-gap narrowing is measured in the 4 X 10(18)-1.5 X 10(19) CM-3 doping level range in very good agreement wi th bulk silicon results. The band-gap narrowing of SiGe strained layer s has been determined for the first time, by means of PL measurements on boron-doped Si0.82Ge0.18 strained alloy up to 4 X 10(19) cm-3. The reduced band gap of the Si0.82Ge0.18 alloy is deduced, taking into acc ount both strain and heavy doping effects and compared to band-gap nar rowing found in Si.