Uniaxial stress and magnetic field dependence of the In- and Tl-related isoelectronic bound excitons in Si

We present the results of uniaxial stress and Zeeman splitting measurements on the photoluminescence spectra of the unique isoelectronic bound excitons found in In- and Tl-doped Si, which are known to exist in two very different configurations. Our results indicate that these two configurations correspond to the two known classes of isoelectronic bound excitons, which differ in the sign of their internal strain field. We also show that the results are not in agreement with previous suggestions that these isoelectronic bound exciton transitions have half-integer angular momenta in both the initial and final states.