PAIRING BETWEEN FAST DIFFUSING DONORS AND SHALLOW ACCEPTORS IN P-CDTE

Defect reactions of mobile interstitial donors D(i) with immobile substitutional acceptors A(Cd) in the space-charge region of Schottky contacts on p-type CdTe are observed at about room temperature. The results are discussed in terms of formation and dissociation of defect complexes (A(Cd)D(i)). For copper diffused samples the dissociation kinetics of a complex, presumably (CuCdCui), is determined. Thc dissociation enthalpy of 0.74 eV leads to the rather low value of 0.2 to 0.3 eV for the migration enthalpy of Cu(i). Furthermore it is shown that thermally stimulated capacitance (TSCap) yields a step with a shape characteristic of defect complex dissociation and drift of the interstitial donor.