Piezoemission of GaSb: Impurities and Bound Excitons

The effect of an uniaxial stress on the impurity and exciton lines is studied. The deformation potentials are determined. The analysis of the uniaxial-stress data shows that the residual acceptor in GaSb is a single acceptor and that the two bound excitons $\beta$ and $\gamma$ are excitons bound to neutral acceptors. We emphasize the importance of the $j-j$ splitting in the $\gamma$ complex. The temperature dependence of the photoconductivity signal reveals the thermal ionization of the complexes. The variation of the intensities of the lines with the temperature and the excitation rate gives evidence concerning the processes by which the injected carriers are bound at low temperature.