Fine structure in the free exciton region of the emission spectrum of γ-InSe

The fine structure of the emission spectrum of γ-InSe in the free exciton region has been investigated. The complete behaviour is given and the quantitative analysis is described in detail. Also, the doublet structure is examined and the possible stacking faults contribution is considered. It is found that the origin of the second peak is bound excitonic. The phonon modes involved in the temperature variation of the exciton energy are obtained from fitting the experimental data to previous theoretical calculations. An explanation is given for the temperature variation of the half width anomaly. (author)