Electronic structure modification of ZnO and Al-doped ZnO films by ions

We present ion beam modifications of the electrical and optical properties of zinc oxide (ZnO) and Al-doped ZnO (AZO) films such as increase of the electrical conductivity, the modification of the optical absorption edge. Ions used here are 100 keV Ne and Ar, and it is shown that the elastic collisions (i.e., collisions between ions and target atoms, and between target atoms without electronic excitation and ionization) play a major role. Also presented are ion-induced growth of grains and redistribution of grain orientation as well as ion-induced degradation of the crystalline quality, knowing that grains with several tens of nanometers in size constitute the films. Their effects on the electrical and optical properties are described.