New Experimental Evidence Concerning the Nature of L, M, and N Lines in ZnSe:Co

The absorption and electroabsorption spectra of ZnSe:Co in the region of the L, M, and N lines are investigated. The experimental data indicate that these lines arise from transitions to excited states of d 7 configuration. The electroabsorption spectrum exhibits new α ° , β ° , γ ° , δ ° , and ϵ ° lines that have intense LO phonon replicas. These lines result from the formation of donor excitons according to the scheme d 7 + h ω → [d 6 e]. The d 7 configuration ground state 4 A 2 is separated from the bottom of the conduction band by 2.565 eV assuming a hydrogen‐like electron binding energy.