IDENTIFICATION OF THE NATIVE VACANCY DEFECTS IN BOTH SUBLATTICES OF ZNSXSE1-X BY POSITRON-ANNIHILATION

We show how positron annihilation can distinguish vacancies in the dif ferent sublattices of a binary compound by performing experiments in Z nS(x)Se(1-x)layers. We identify the Se vacancies (V-Se) in N-doped and the Zn vacancies (V-zn) in Cl-doped material by the shape of the core electron momentum distribution. The charge of the defect involving V- Se is neutral or negative in p-type ZnSxSe1-x, suggesting that Vs, is complexed with an acceptor. The concentration of the Vs, complexes is high (greater than or equal to 10(18) cm(-3)), indicating that their r ole is important in the electrical compensation, of p-type ZnSxSe1-x.