Effects of growth conditions on the emission properties of ZnO films prepared on Si(100) by rf magnetron sputtering

ZnO films were prepared on Si(100) substrates using rf magnetron sputtering and the correlations between the growth conditions and the resultant film properties were discussed. The intensity of the visible emission related with intrinsic defects in ZnO film was dramatically suppressed by increasing the O-2/Ar + O-2 ratio in the growing ambient, which provides further evidence that the visible luminescence of ZnO originates from the oxygen vacancy or Zn interstitial related defects. It was also certain that the exciton related emission of ZnO is strongly dependent on the size of the micro-crystallites forming the film, showing the noticeable increase of the emission intensity with increasing grain size.