Ultrahigh-resolution photoluminescence studies of excitons bound to boron in silicon under uniaxial stress.

Abstract

The effects of uniaxial stress on the no-phonon photoluminescence spectrum of the boron bound exciton in silicon have been investigated using ultrahigh-resolution Fourier-transform spectroscopy. Under stresses of 0 to 25 MPa, in the 〈001〉, 〈110〉, and 〈111〉 directions, up to 25 components with linewidths of less than 10 \ensuremath{\mu}eV have been resolved. A theoretical model, extending the shell model, has been developed to interpret the splittings in the bound-exciton energy levels. This includes terms expressing electron-stress, hole-stress, electron-hole, hole-hole, and valley-orbit interactions, with spherical and anisotropic corrections. The model fits the experimental data very closely, and gives values for the magnitude of the interactions.