Characteristic properties of Raman scattering and photoluminescence on ZnO crystals doped through phosphorous-ion implantation.

P-doped ZnO was fabricated by means of the ion-implantation method. At the Raman measurement, the blue shift of the E₂ ^high mode and A₁(LO) phonon of the inactive mode were observed after the P-ion implantation. It suggested to be caused by the compressive stress. Thus, Hall effect measurement indicates that the acceptor levels exists in P-doped ZnO while still maintaining n-type ZnO. From the X-ray photoelectron spectroscopy, the chemical bond formation of the P2p_3/2 spectrum consisted of 2(P₂O₅) molecules. Therefore, the implanted P ions were substituted to the Zn site in ZnO. From the photoluminescence (PL) spectra, P-related PL peaks were observed in the energy ranges of 3.1 and 3.5 eV, and its origin was analyzed at P_Zn-2V_Zn complexes, acting as a shallow acceptor. With increasing temperatures, the neutral-acceptor bound-exciton emission, (A⁰, X), shows a tendency to quench the intensity and extend the emission linewidth. From the relations of the intensity and the linewidth as a function of temperature, the broadening of linewidth was believed to the result that the vibration mode of E₂ ^high participates in the broadening process of (A⁰, X) and the change of luminescent intensity was attributed to the partial dissociation of (A⁰, X). Consequently, these facts indicate that the acceptor levels existed in P-doped ZnO layer by the ion implantation. [ABSTRACT FROM AUTHOR]