**7. Conclusions**

*21st Century Surface Science - a Handbook*

and adversely affects properties.

Aerosol deposition technique, in terms of homogeneous, continuous, and applicability to large area TCO, is a convenient method for industrial production of materials that has not been studied much before. As it is known, new-generation ceramic integration technologies require device performance improvement for various applications such as size reduction and/or micro-mechanical systems, image technologies, fuel cells, and optical devices. Common industrial applications of these devices are high-speed coatings and productions that bring low processing temperatures and thin lithographic processes in ceramic coatings. "Ceramic powder aerosol deposition method" has many advantages to meet many of the requirements mentioned above when compared to other conventional film/coating applications. While ceramic material productions generally require sintering over 1000°C, this makes it impossible to integrate metal, glass, and even polymers with relatively low melting point with functional ceramics. On the other hand, high-temperature film applications trigger high-temperature crack formations and substrate-coating incompatibilities and discontinuities, as well as long processing times. Especially in film-type applications, the substrate-coating incompatibilities and surface discontinuities will adversely affect the optical, electrical, and mechanical properties of the device for the application and also decrease its performance. Similar results were observed in our previous research studies in the form of surface cracks and unexpected decrease in electrical properties as a result of ZnO-based coatings obtained by magnetron scattering method, which requires additional heat treatment up to 700°C. The main output of the aerosol deposition method in the development of a new technique and industrial product with high-speed coating efficiency, low processing temperature, and even at room temperature reduces costs and production time

The basic principle of the technique is based on the conversion of some of the kinetic energy of the previously prepared and suitable form of fine ceramic particles with the substrate at high speeds, into both interparticle and interparticlebinding energy. In this context, while the aerosol deposition method offers many advantages compared to traditional thin/thick film methods and thermal spray coating techniques, it has not been fully understood as a new method, revealing the open points for the research. A schematic of this method is given in **Figure 3**.

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**Figure 3.**

*Room temperature aerosol deposition system.*

Due to the cost and difficulty of finding indium in TCO, cost-effective and alternative materials with the same properties are needed. In addition to high conductivity TCO, the development of materials other than ITO has increased in few years. ITO's cost and potential supply limit are among the reasons for research in this field.

Besides, not only for the metallic and/or ceramic substrates but also for the substrates with low melting point or polymers need to be focused on new semiconductor fabrication technologies. At this point, room temperature aerosol deposition method seems to be an alternative technique and may bring a new perspective in high-technology semiconductor applications.

*21st Century Surface Science - a Handbook*
