SELF-COMPENSATION OF A DONOR IMPURITY BY NEUTRAL COMPLEXES IN BISMUTH-DOPED LEAD-TELLURIDE

The self-compensation of the doping effect of an impurity in a IV-VI s emiconductor by neutral complexes consisting of a vacancy and two impu rity atoms is calculated. The entropy of the complexes is calculated. The thermodynamic potential is minimized with respect to the concentra tion of doubly charged, isolated vacancies and the concentration of co mplexes. The results of the calculations are compared with experimenta l data on the doping of lead telluride by bismuth with an excess of te llurium with respect to stoichiometry. The incorporation of complex fo rmation substantially improves the agreement between theory and experi ment.