Point defects in germanium: Reliable and questionable data in radiation experiments

This review paper outlines some important findings in the field of radiation-produced defects in Ge. Because of poor identification of point defects in this semiconductor the interpretation of electrical and optical data, especially those obtained in low-temperature radiation experiments, has been given by a common analogy with the known defects in Si. However, there are many examples of striking dissimilarities between defect production and annealing processes in both materials. First of all, this is true for the Frenkel pairs as primary defects in irradiated materials. Their properties and behavior in n- and p-Ge are a major focus of discussion in this review. All important data concerning the annealing stages of defects taking place below room temperature are scrutinized to accumulate reliable information on the native defects in Ge. Together with this, the data obtained with the help of such nuclear physics techniques as the Huang diffuse scattering of X-rays, γ–γ perturbed angular correlation, etc., are also briefly discussed.