Lattice location of the group V elements Sb, As, and P in ZnO

Abstract

Modifying the properties of ZnO by means of incorporating antimony, arsenic or phosphorus impurities is of interest since these group V elements have been reported in the literature among the few successful p -type dopants in this technologically promising II-VI compound. The lattice location of ion-implanted Sb, As, and P in ZnO single crystals was investigated by means of the electron emission channeling technique using the radioactive isotopes 124 Sb, 73 As and 33 P and it is found that they preferentially occupy substitutional Zn sites while the possible fractions on substitutional O sites are a few percent at maximum. The lattice site preference is understandable from the relatively large ionic size of the heavy mass group V elements. Unfortunately the presented results cannot finally settle the interesting issue whether substitutional Sb, As or P on oxygen sites or Sb Zn -2 V Zn , As Zn -2 V Zn or P Zn -2 V Zn complexes (as suggested in the literature) are responsible for the acceptor action. However, the fact that the implanted group V ions prefer the substitutional Zn sites is clearly a strong argument in favour of the complex acceptor model, while it discourages the notion that Sb, As and P act as simple chemical acceptors in ZnO.