Effect of oxygen partial pressure and annealing on nanocrystalline p-type ZnO:Sb thin films

We have investigated the effect of oxygen partial pressure and annealing on nanocrystalline p-type Sb-doped ZnO thin films, grown by pulsed laser deposition, with hole concentration of 6.5 × 1018/cm3 and mobility of 53 cm2/V-s. Uses of higher working pressure or annealing are found to reduce carrier concentration. A strong correlation is observed between carrier concentration and the violet (3.02 eV) emission related to free Zn-vacancy; stronger the violet emission, smaller the carrier concentration. In contrast to earlier suggestion of using higher oxygen pressure for obtaining p-type conductivity, the present results show a deterioration of the quality of film.

► Highest hole mobility achieved in p-type ZnO:Sb films.
► High oxygen partial pressure reduces hole mobility.
► Higher oxygen growth pressure and annealing increase the Zn-vacancy.
► Annealing causes carrier concentration to reduce.