Hexagonal Mg

x

Zn

1-x

Oalloy layers with 0≤x

<

0.3 have been grown by plasma-assisted molecular beam epitaxy on sapphire (006) substrates. Their crystal structures are characterized by X-ray diffraction spectroscopy. The resonant Raman spectra were measured using 325 nm line from He-Cd laser by backscatte-ring geometry. The long wavelength frequencies of ZnO-like optical phonons measured in the resonant Raman spectra can be expressed as linear functions of x:ω(LO)=(580+147x)cm

-1

.ZnO/Mg

0.12

Zn

0.88

Osingle quantum well (SQW) with 1.5 nm ZnO well width was grown on sapphire substrate. In the PLspectra at 5 K

Pband located at 3.371 eV was observed. At excitation densities higher than 76 kW/cm

2

the Pband shows a typical super linear increase characteristic. With increasing the excitation density further

the Pband converges gradually at the saturation value of 3.354 eV with significant narrowing. It was attributed to the gradually enhanced exciton-exciton scattering. The integrated emission intensity versus excitation density follows the relation of

I

ex

3.13

. This superlinear increase indicates the typical properties of a super-radiation recombination.