Photoluminescence characterization of UHV/CVD grown multi-quantum well structures

Ultra-high vacuum chemical vapor deposition is particularly suitable for growth of band gap engineered Ge_xSi_1?x structures, since abrupt epilayers with a very high degree of uniformity can be obtained. We have grown multi-quantum well structures over a range of well widths and have characterized them by photoluminescence spectroscopy. We have observed prominent quantum well-related features that shift to higher energy in samples with narrower well widths. Spectra taken from various points on a 75 mm wafer show a maximum variation of ±3 meV in position of the no phonon peak in the 35Å well multi-quantum well sample.