Exchange energy and oscillator strengths of excitons in cadmium sulfide

The Hamiltonians of A and B excitons are derived, taking into account the linear k term of conduction and valence band, the longitudinal transverse splitting, and the exchange energy. We show that the data on A-excitonic polaritons provide the parameters of B-excitonic polaritons. We deduce (i) the exchange energy, scrE=0.23±{}0.07 meV, from available data on A-excitonic polaritons, and (ii) the parameter q₇ (determining the B-hole wave function in Gutsche-Jahne notation), q₇²=0.39, from available data on B-excitonic polaritons.