Photoluminescence of a pseudomorphic Si1-yCy/Si MQW structure under pressure

We have measured photoluminescence (PL) spectra of a pseudomorphic Si1-yCy/Si (y = 0.0045) multiple quantum well (MQW) structure under hydrostatic pressure (0 to 8 GPa) and at low temperatures (10 to 70 K). The MQW-related emission at energies below the Si band gap consists of bound and free exciton zero-phonon lines and related Si-Si TO phonon replicas. All MQW-related PL peaks shift to lower energy with increasing pressure. The dependence of PL-peak intensities and energies on excitation power density; temperature, and pressure are consistent with a type-I band alignment throughout the pressure range investigated. Furthermore, the total band offset aid tie activation energies involved in the decay of the free and bound exciton emission show only a very small change with pressure.