Visible luminescence and structural property of GaSe1−xSx (0≤x≤1) series layered crystals

Luminescence and structural properties of GaSe1−xSx (0≤x≤1) series optical materials were characterized using photoluminescence (PL) and piezoreflectance (PzR) measurements at 300 K. From the comparison of PL and PzR spectra, the whole series GaSe1−xSx (0≤x≤1) layers were confirmed to possess three different kinds of stacking phase when increasing the sulfur composition from x=0 to 1. Observing the peak positions of the PL spectra the light emissions of whole series GaSe1−xSx are shown to cover from red to blue visible region. The PL and PzR spectra of whole series GaSe1−xSx are analyzed. The structural variations in the layers are discussed. Based on the experimental results together with referring to previous band-structure calculations, a probable band scheme which indicating the transition assignments in the fundamental edge of GaSe1−xSx is proposed.