Abstract
Absorption and infrared luminescence excitation spectra are presented for GaP:Co2+. Novel spectral features are observed and interpreted within the framework of the crystal-field model as spin-forbidden intra-impurity transitions. The crystal-field calculations are conducted for Dq=475 cm-1, B=395 cm-1, lambda =-135 cm-1 and 4.0<or=C/B<or=4.8. The experimental results are best described by C/B=4.6+or-0.1. A photoionisation band is observed in the excitation spectrum and from its onset the position of the ground Co2+(3d7) level is shown to be 1.85+or-0.1 eV below the conduction band edge.