Zinc oxide (ZnO) nanowires were prepared on silicon substrate via a novel method of polymer complexation-sintering by using polar long-chain polymer (such as PAM and PVA) as self-assembling grid backbone. These ZnO nanowires were characterized by FE-SEM and HRTEMtechniques and their optical pro-perties were studied by photoluminescence spectroscopy and UVabsorption spectroscopy at room temperature. The mechanism of the ZnO nanowires growth and their photoluminescence

and the relation between process conditions and the mechanism are discussed.The ZnO nanowires

with diameter of about 50~80 nm and the lengths

>

4 μm

are hexagonal wurtzite single-crystalline and grown along the

c

-axis orientation preferentially. These nanowires have a strong UV emission band and a weak blue band as well as a strong UV light absorption. With decreasing the nanowires diameter

a blue shift of absorption peak appears.Polymer concentration and the complexing ratio of polymer to Zn

2+

are the key factors controlling the self-assembling growth of ZnO nanowires. The mesh size and distribution of polymers

which are confined by the concentration of the polymer solution

control the diameter of the nanowires. Well vertically grown nanowires initiate only from the site that Zn

2+

is complexed with the polymer

which forms the ideal nuclei

and the nuclei number is dependent on the complexing ratio of the polymer and Zn

2+

.The sintering temperature

sintering ambience and annealing condition affect photoluminescence of the ZnO nanowires. By controlling the sintering and thermal annealing conditions

the quality of the nanowires can be improved

and therefore

the better optical properties of the ZnO nanowires can be achieved. In high quality ZnO nanowires

a sharp strong emission peak at~393 nm appears due to the ultra-violet near band-edge emission of wide band gap ZnO

namely the free-exciton annihilation through an exciton-exciton collision process. The phenomena of UV band emission at room temperature might be attributed to the radial quantum confinement effect from ZnO nanowires. It can be concluded that the improvement of crystal quality

i.e.

decrease of impurities and structure defects such as oxygen vacancies

stacking faults and dislocations

and the quantum confinement effect related to the nanostructures are responsible for the intensity increase of the observed UV emission at room temperature.