Abstract:

ZnO semiconductor powders doped with Al₂O₃were synthesized via solid synthesis. The inf1uences of Al₂O₃ doping content , calcination temperature and soaking time on the resistivity of ZnO powders were then analyzed by means of XRD. Experimental results show that ZnAl₂O₄ spinel may exist in ZnO semiconductor powders and the electric conductivity may decrease when the doping content of Al₂O₃ overruns O. 5 % in molar ratio , and that ZnO powders with low resistivity can be obtained when enough Al³⁺ enter the ZnO crystal lattice at a certain calcinations temperature for a certain soaking time. However , excessive calcination temperature and soaking time may result in the formation of ZnAl₂O₄ spinel from Al₂O₃ and ZnO , which makes the replacing ratio of Al³⁺ for Zn²⁺ decrease and the electron scattering occur, thus increasing the resistivity of ZnO powders. It is also indicated that the synthesized ZnO powders are of a resistivity of 18kΩ•cm when the reaction system is calcined at 1300℃ for 3 h with a Al₂O₃ doping content of O.5% .

Key words: zinc oxide, semiconductor powder, alumina, doping, resistivity