Effects of post-annealing on structural, optical and electrical properties of Al-doped ZnO thin films

Activation of visible up-conversion luminescence in transparent and conducting ZnO:Er:Yb films by laser annealing

“…This increase in resistivity can be ascribed to either the decrease of oxygen vacancies or to the chemisorption of O 2 that might have been trapped at the grain boundaries during air annealing. Both cases would reduce the density of donor sites and/or the RE interstitial atoms, resulting in the decrease of the carrier concentration and a rise of the potential barrier, which would consequently reduce the mobility of the films [14][15][16]. The vacuum annealing of the films resulted in a resistivity of 4×10 -1 Ω·cm, which is only one order of magnitude higher than the as-deposited ones.…”

“…In particular, the conduction mechanism of ZnO films is mainly due to the electrons supplied from the donor sites associated with oxygen vacancies and zinc interstitials. The as-deposited ZnO films doped with metallic Er and Yb species showed higher electrical conductivity than pure ZnO films due to the contribution of Er 3+ and Yb 3+ ions incorporated at the substitutional sites of Zn 2+ ions, as well as the presence of the aforementioned oxygen vacancies and zinc interstitials [14]. The resistivity values of the as-deposited film and of the samples subjected to different annealing methods were calculated from the electrical sheet resistance measurements.…”

Room temperature ferromagnetism in ZnO prepared by microemulsion

“…All the XPS spectra were referenced to the surface impurity C 1s line (284.8 eV) binding energy. 17,18 As can be seen, annealing in H 2 and air both decrease the concentration of O deficient region significantly. Since the ferromagnetic magnetization from V O clusters was almost unchanged, and only isolated F center has magnetic moment of 1 μ B , 6,16 we can conclude that the annealing in H 2 will effectively remove the isolated F centers.…”

Effect of grain-boundaries on electrical properties of n-ZnO:Al/p-Si heterojunction diodes

“…On the other hand, with increasing grains as a function of AZO layer thickness can increase the mean free path of electrons. In fact, the energy of electrons with increasing AZO film thickness will be conserved with long mean free path, 24 which in turn will reduce the scattering loss 25,26 and trapping of charge carriers, resulting in a decrease in resistivity (Figure 4). …”