Optical properties of Cu− centres in NaCl crystals

Abstract

For a systematic study of the isoelectronic series of s2-type centres, absorption, excitation and emission spectra of Cu− centres in NaCl crystals are investigated in the ultraviolet and vacuum ultraviolet spectral range at temperatures from 77 to 300 K. Two weak absorption bands were observed at 269 and 256 nm in addition to four bands at 288, 272, 232, and 189 nm which are assigned to the A, B, C and D bands of s2-type spectra, respectively, while only two emission bands peaking at 423 and 318 nm were detected. These results of Cu− centres are compared with those of the hitherto investigated s2-type centres.