While the first comparison of shallow bound exciton photoluminescence between natural Si and highly enriched S 28 i dramatically demonstrated the importance of inhomogeneous isotope broadening, the transitions in S 28 i were in fact too narrow to be resolved with the then available instrumental resolution of 0.014 cm-1. We report results for the boron bound exciton transition in highly enriched S 28 i using a novel apparatus for photoluminescence excitation spectroscopy based on a tuneable single-frequency laser source with sub-MHz resolution. Twenty well-resolved doublets, exhibiting a B 10 - B 11 isotope splitting, are observed in the new spectra for S 28 i with isotopic enrichment >99.99%. Linewidths as narrow as 0.0012 cm-1 (150 neV) full width at half maximum are observed for the most highly enriched sample.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2009 Nov 11|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics