Photoluminescence properties and energy transfer of Eu2+/Pr3+ codoped GeS2-Ga2S3-CsCl chalcohalide glasses

► Prominently enhanced Pr3+ visible emissions is obtained with the codoping of Eu2+. ► The ECS of the Eu2+/Pr3+ codoped glass is almost three times of the Pr3+ singly doped glass. ► High ET efficiency up to 80% from Eu2+ to Pr3+ is obtained in the codoped glasses.