Defect properties of implanted boron in ZnSe

Microscopic properties of B in ZnSe are investigated by means of beta-radia tion-detected nuclear magnetic resonance (beta-NMR). After implantation of spin-polarized, radioactive B-12 nuclei in nominally undoped ZnSe single cr ystals at stationary concentrations of similar to 10(8) cm(-3), three diffe rent B-defect configurations can be distinguished. First, an unperturbed fr action at cubic lattice sites, identified as substitutional B-Zn(+) by a di polar linewidth analysis. Second, a smaller part of. "perturbed" probes att ributed also to B-Zn(+) but with nearby Se vacancies. And third, a paramagn etic configuration, tentatively assigned to the isolated interstitial B-i(2 +) Temperature-dependent measurements shaw a conversion of B-i to B-Zn with an activation energy of E-a = 0.61(3) eV which we attribute to B-i migrati on. After this annealing stage we find a B-Zn fraction of about 85%, i.e., an excellent ''doping efficiency." A substantial inward relaxation of the n earest: Se and next-nearest Zn atoms around the B-Zn(+) donor is observed a nd compared with model predictions. [S0163-1829(99)05104-8].