PHOTOLUMINESCENCE OF EXCITONS BOUND TO THE ISOELECTRONIC HYDROGEN-RELATED DEFECTS B-80(1.1470 EV) AND B-19(1)(1.1431 EV) IN SILICON

Photoluminescence spectra of excitons bound to isoelectronic defects B80 and B191 (1.147 00- and 1.143 14-eV principal no-phonon lines, respectively), created in phosphorus-doped silicon grown in a hydrogen atmosphere as the result of irradiation by thermal neutrons, were investigated in magnetic fields up to 12 T and under uniaxial stress in 001, 111, and 110 crystallographic directions using high-resolution Fourier-transform spectroscopy. The symmetry of these defects was determined to be C1. The ground state of the bound excitons is split into a triplet. The lowest state, which is not evident in the zero-field spectra, results in an additional spectral component under applied magnetic field. Using group theory, we constructed a Hamiltonian for excitons bound to the isoelectronic centers B80 and B191, which takes into account electron-hole coupling and interactions with external perturbations. g-factors g1/2x=1.3, g1/2y=1.2, g1/2z=0.6, g3/2x=0.9, g3/2y=1.2, g3/2z=1.7 for B80 and g1/2x=1.35, g1/2y=1.6, g1/2z=0.7, g3/2x=0.9, g3/2y=0.7, g3/2z=1.56 for B191 were determined from the best fit to the experiment. © 1995 The American Physical Society.