Enhancement of phosphorus solubility in ZnO by thermal annealing

We have demonstrated the effect of annealing temperature on the diffusion density of phosphors in zinc oxide. The P-dopant P430 was sprayed on ZnO pellets and annealed at different temperatures from 500 to 1000℃ with a step of 100℃ for one hour using a programmable furnace. The concentration of P was controlled by varying the annealing temperature and the maximum solubility of P(3% At) was achieved at annealing 800℃ determined by energy dispersive X-ray diffraction(EDX) measurements. X-ray diffraction(XRD) confirmed the hexagonal structure of ZnO and showed that the growth direction was along the c-axis. We observed a maximum up shift in the(002) plane at an annealing temperature of 800℃, suggesting that P atoms replaced Zn atoms in the structure which results in the reduction of the lattice constant. Room temperature photoluminescence(PL) spectrum consists of a peak at 3.28 eV and related to band edge emission, but samples annealed at 800 and 900℃ have an additional donor acceptor pair peak at 3.2 eV. Hall effect measurements confirmed the p-type conductivity of the sample annealed at 800℃.

Enhancement of phosphors-solubility in ZnO by thermal annealing