Zinc oxide is an excellent semiconductor material with a band gap of 3.37 eV at room temperature and an exciton binding energy of 60 meV. It has excellent optical, electrical and catalytic properties. Zinc oxide is piezoelectric and can be used in optoelectronic devices, sensors, catalysts, and composites. Zinc oxide can not only be made into a good semiconductor and piezoelectric film, but also can be made into a good transparent conductive film by doping, and the raw materials are easy to obtain, cheap, less toxic, and various preparation methods can be adapted to different needs. One of the most widely used film materials with development potential.
With the emergence and further development of the third generation of semiconductors, and with the introduction of new energy into people’s daily topics, people have been more and more extensive research on zinc oxide, and extensive research on the properties of Zinc oxide optics.
Many scientists have studied the optical properties of doped zinc oxide. The researchers prepared Ag-doped zinc oxide nanostructures by wet oxidation doping process and studied their microstructure and optical properties. High-power electron transmission electron microscopy directly shows that Ag is already present in the zinc oxide nanowires. XPS shows that Ag is present in the zinc oxide in an oxide chemical state. The PL spectrum shows that the UV excitation of Ag-doped zinc oxide is more than three times that of pure zinc oxide, because the Ag photocarriers are more likely to escape than the Zn ions. If such a material is made into a light-emitting device, the luminous efficiency of such a device is greatly improved.
Domestic and foreign scientists have also tried to double-doped zinc oxide to further change the optical properties of the material. The researchers studied the optoelectronic properties of Al-Ga co-doped zinc oxide films by annealing. The sample resistivity at 450 ° C annealing temperature decreases and the carrier concentration increases. Al-Ga co-doping increases the optical gap of zinc oxide and shifts the zinc oxide Fermi level. Other researchers studied the photocatalytic properties of Pd-doped zinc oxide. The results show that all Pd-doped zinc oxide exhibits better photocatalytic performance than pure zinc oxide. It has also been found that Pd-doped zinc oxide enhances absorption in the visible region and increases the separation rate of photogenerated charges. This improvement in photocatalysis contributes to an increase in light absorbing ability and a separation rate of photogenerated carriers.