Change in Exciton Absorption with Laser Light in GaSe

Abstract

Absorption spectra of excitonic region in GaSe were measured at 2 K and 77 K, using a pulsed dye laser. Disappearance of an exciton line was observed. This phenomenon is attributed to a transition from an excitonic state to an electron-hole plasma state. This transition is possibly caused by a collision process between two excitons.