Laser gettering of structural-impurity defects in the contacts of metal–intrinsic CdTe with a Schottky barrier

The influence of surface laser treatment on structural properties of metal–intrinsic CdTe contacts was investigated by metallographic method and scanning electronic microscopy techniques. At critical intensities of pulse laser irradiation on the metal–CdTe boundary re-structuring of structurally impurity defects in a solid state occurs. A defect system of large grains of single crystalline CdTe is formed. Separate clusters were ordered over a long range and formed their own “crystalline sublattice”, probably, of trimetric configuration. A diameter of the cluster in nodes of such a lattice equalled 1–3 μm, while distance between clusters was of about 10–15 μm. As radiation dose was increased the clusters acted as getters of dot defects. At optimal modes of laser irradiation their sizes increased in 2–3 times, consequently leading to decrease in concentration of deep levels in the semiconductor. As has shown investigation of the I–V and C–V characteristics such processes caused reduction of GR component of a current, promoting field charge transfer mechanisms in contacts with a Schottky barrier.