Growth of semiconducting CdF2:Ho3+ crystals and study of their optical and transport properties

A method for growing CdF2:Ln3+ crystals (Ln lanthanide) is presented which results in semiconducting samples without any subsequent annealing. It is found that the main preparation parameters act on the optical and transport properties through a common parameter Esub(σ). The infrared absorption of the samples as well as their conductivity are then analysed in the frame of a model with impurity-banding and hopping conductivity, resulting in information on the impurity density of states. (author)