抄録
ESR measurement has been carried out at X-band on isolated Fe3+ (3d5, 6S) in CdSe. The spin Hamiltonian parameters for Fe3+ are estimated at 1.5°K as follows: g=2.043±0.002, a=(103±5)×10−4 cm−1, D=(602±3)×10−4 cm−1, and F=(−11±5)×10−4 cm−1. The influence of charge transfer from Fe3+ to the surrounding ligands upon these parameters is discussed.
Change of the valency of iron impurities caused by illumination is studied through the change of the intensity of Fe3+ ESR signal. Following processes are elucidated. Light of 0.8 to 1.1 μ excites holes from Fe3+ to the surrounding Se2− ions; the excited holes are liberated thermally into the valence band. Light of about 7.4 μ excites electrons from Fe2+ to the conduction band. Light of around 1.8 μ liberates holes from cadmium vacancies; a part of the liberated holes migrates through the valence band to Fe2+. Fe3+ captures electrons from the conduction band, viz, acts as a recombination center for electrons.
