Published online by Cambridge University Press: 10 February 2011
Recent low-temperature photoluminescence (PL) studies will be discussed for coherent Si1-xGex. and Si1-xGexCy alloy multiple quantum wells on Si (001) substrates grown by either ultra-high vacuum chemical vapour deposition or solid source molecular beam epitaxy. An in-plane applied-stress technique will be described which removes systematically band edge degeneracies revealing the lower, PL-active CB. Applied-stress data taken with this technique at ultra-low excitation intensity proved intrinsic type II CB alignment in SiGe on Si (001). Apparent type I alignment observed at higher intensity will also be discussed. New applied stress PL results are presented for Si1-x-yGexCy quantum wells under various grown-in stress condition