Infrared Studies of Defects in ZnS Crystals Double‐Doped with Li and Al, Ga, and In

Infrared absorption (360 to 500 cm−1) is studied in ZnS crystals doped with both, lithium and a group IIIA dopant. The dominant bands in the obtained absorption spectra can be ascribed to the localized vibrational modes of two types of defects: 1) unassociated Li on a Zn site, Li−Zn, and 2) pairs comprising substitutional Li on a Zn site and substitutional group IIIA impurity on the nearest Zn site, M+Zn‐Li−Zn (M = Al, Ga, or In). Li in ZnS is found to have a considerable effect on atomic interactions in the neighbouring region and, therefore, cannot be regarded as a pure mass defect.