Spectroscopy of Excited Acceptor States in GaP

Luminescence excitation spectroscopy of donor-acceptor pair recombination in GaP is reported. We observe $s$ and $p$ excited states of C, Mg, and Zn acceptors, and deduce acceptor binding energies and Luttinger valence-band parameters (${\gamma }_1=4.04\mathrm{}$, ${\gamma }_2=0.53\mathrm{}$, and ${\gamma }_3=1.26\mathrm{}$). Directly obtained information on the interaction between donors and acceptors characterizes the acceptor state and confirms observation of the $1S_{\frac{1}{2}}$ level.