Nanotechnology and nanomaterials

Influence of anneal temperature on morphology, structure and chemical composition of zinc oxide films printed by 3D printer
Yermakov M.S., Dobrozhan O.A., Opanasyuk A.S.
Department of Electronics and Computer Technology, Sumy State University. Rimsky-Korsakov str., 2, Sumy, UA-40007, Ukraine.
E-mail: m.yermakov@ekt.sumdu.edu.ua

Zinc oxide (ZnO) is of considerable interest to researchers due to its feasibility. This material has high radiation, chemical and thermal resistance and in the future can be widely used in the creation of elements of transparent electronics, gas sensors, ultraviolet detectors and more. Zinc oxide is a straight-band n-type semiconductor belonging to the group of compounds A2B6, its band gap at 300 K is ~ 3.27 eV. ZnO films can be used as elements of high-efficiency electronic auto emitters. a variety of optoelectronic devices, liquid crystal displays, photodiodes, window and conductive layers of solar panels and other electronic devices due to the high conductivity and transparency in the visible spectrum.
ZnO films were obtained on the cover glass by printing ink based on a suspension of nanocrystals synthesized by the polyol method. Because the ink contained organic substances as solvents, it was annealed for one hour in air and vacuum to remove uncontrolled impurities after film application. The annealing temperature was varied in the range from 200 °C to 400 °C.
As a result of research, it was established that the films were nanostructured, contained zinc and oxygen atoms, and the distribution of these elements by area was uniform. In addition to the main components of the material, the method of EDAX in the layers also recorded the carbon that is part of the developed ink. In some cases, because the applied films were thin, a peak of the Na element belonging to the glass substrate was observed. It was found that the concentration of carbon in the films decreased with increasing annealing temperature. However, the results of the study show that we failed to burn all the carbon that got into the organic films, so the time of their annealing in future work should be increased. It should be noted that during annealing the adhesion of the films to the glass substrate deteriorated sharply. This is due to the occurrence of large thermal deformations in the system, as the coefficients of linear expansion of materials differ significantly (αsl = 5.9 × 10-6 ℃, αZnO = 29.0 × 10-6 °C).
Thus, the annealing conditions of printed ZnO films are established, which allow to burn out impurities without disturbing the nanostructured state of the layers.