Magneto-Optical Studies of Excited States of the Cl Donor in CdS

Abstract

We have studied the $2s$ and $2p$ levels of the Cl donor in CdS by two methods: first, by observing "two-electron transitions" in which an exciton bound to the neutral donor Cl decays, leaving the donor in its $n=2$ excited states; second, by observing Raman-scattering transitions between the $n=1$ and $n=2$ donor levels. We have accurately measured the positions of the $2{p}_{x}$, $2{p}_{z}$, and $2s$ levels relative to the $1s$ state to be 24.36 \ifmmode\pm\else\textpm\fi{} 0.02, 24.19 \ifmmode\pm\else\textpm\fi{} 0.02, and 23.88 \ifmmode\pm\else\textpm\fi{} 0.02 meV; the anisotropy factor $\ensuremath{\alpha}=0.054\ifmmode\pm\else\textpm\fi{}0.005$; and the electron mass ${m}_{\ensuremath{\perp}}=0.190\ifmmode\pm\else\textpm\fi{}0.002$. With less precision, we have measured ${m}_{\ensuremath{\parallel}}=0.180\ifmmode\pm\else\textpm\fi{}0.010$ and estimated the donor binding energy to be 32.7 \ifmmode\pm\else\textpm\fi{} 0.4 meV.