Direct and indirect excitonic emission in GaSe

Photoluminescence spectra of undoped crystals of the layer semiconductor GaSe have been measured from 80 K up to room temperature. The direct and indirect excitonic emissions are clearly observed in the intrinsic part of the spectrum. Moreover, a detailed analysis of the luminescence intensity has been made as a function of exciting power and temperature, allowing one to ascribe some lines of the intrinsic part of emission spectrum to direct and indirect excitons bound to localized impurity levels in the energy gap of GaSe.