The difficulty in the fabrication of p-type ZnOhinders the development of ZnO-based devices. Group-Ⅰand group-V elements substituting for Zn and Ocan respectively form the different acceptor dopants. Park C Hcalculated the energy levels of different acceptor dopants in ZnO

and it is found that group-Ⅰ elements substituting for Zn are of a shallower acceptor level than group-V elements substituting for O. Especially the acceptor level of Li substituting for Zn (Li

Zn

) is 0.09 eV

which is the shallowest value among the energy levels of acceptor dopants in ZnO reported. However

when Li atom substitutes for Zn

it will easily be accompanied by the formation of interstitial Li (Li

i

)

which is likely to be shallow donor. This causes the p-type doping to be limited by the formation of a Li

Zn

-Li

i

complex donor. Based on above

Li was used as the acceptor dopant substituting for Zn in this work. In order to repress the formation of Li

i

nitrogen was used as a codopant with lithium by a two step annealing process to form Li

Zn

-N complex acceptor.