Key points are not available for this paper at this time.
The exciton spectrum of AgI, CuI, CuBr, and CuCl is discussed and various peaks attributed to several coexisting crystal modifications. The shift of the peaks with alloy concentration in the pseudobinary systems formed with these compounds is reported and interpreted. The absorption and reflection spectra of these materials and their alloys for energies between the energy gap and 10 eV is reported and the structure attributed to transitions between regions of the valence band lying below the highest maximum and parts of the conduction band higher than the lowest minimum. These spectra are compared with the corresponding spectra of other zincblende- and wurtzite-like materials.
M. Cardona (Tue,) studied this question.