**4. Conclusions**

In summary, we studied the structural and optical properties and the sheet resistance ability of AZO layers deposited by the ALD technique onto glass and PET substrates. LC devices with transparent AZO electrodes were successfully fabricated, and the measured driving voltage and response time values show the great potential of AZO for integration as functional transparent conducting material. We expect that the above demonstrations will be relevant for further applications in high-end optoelectronics.

**Author Contributions:** Conceptualization, V.M., S.H.L., and K.Y.H.; methodology D.D., B.B., S.P., and D.P.; software, S.P., C.-L.T., V.S., and B.N.; formal analysis, V.M., S.H.L., and K.Y.H.; resources D.D., V.M., and S.H.L.; writing—original draft preparation, D.D., and V.M.; writing—review and editing D.D., C.-L.T., V.M., B.B., S.P., D.P., V.S., B.N., S.H.L., and K.Y.H.; visualization, D.D., C.-L.T., V.M., S.P., D.P. and V.S.; supervision, V.M., S.H.L., and K.Y.H.; funding acquisition D.D., V.M., and S.H.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Bulgarian Science Fund under the Grant No. K-06-H-28/8 and the Ministry of Science and Technology (MOST), Taiwan, under the Grant No.: MOST 107-2221-E-009-120-MY3 and MOST 109-2927-I-009-507. We are grateful for the support from the Higher Education Sprout Project of the National Chiao Tung University and Ministry of Education (MOE), Hsinchu, Taiwan. Research equipment from the distributed research infrastructure INFRAMAT (part of the Bulgarian National roadmap for research infrastructures), supported by the Bulgarian Ministry of Education and Science under contract D01-284/17.12.2019, was used for AFM measurements.

**Acknowledgments:** The authors would like to thank P. Terziyska from the ISSP, BAS, Bulgaria for determining the AZO layer's thickness and to Marina Vasileva from the IOMT, BAS, Bulgaria for the measurement of the optical spectra. The authors gratefully acknowledge the financial support provided by the Bulgarian Science Fund under the grant number K-06-H-28/8 and the Ministry of Science and Technology (MOST), Taiwan, under the grant numbers MOST 107-2221-E-009-120-MY3 and MOST 109-2927-I-009-507 (Bulgarian–Taiwanese PPP exchange program). We are grateful for the support from the Higher Education Sprout Project of the National Chiao Tung University and Ministry of Education (MOE), Taiwan. Research equipment from the distributed research infrastructure INFRAMAT (part of the Bulgarian National roadmap for research infrastructures), supported by the Bulgarian Ministry of Education and Science under contract D01-284/17.12.2019, was used for AFM measurements.

**Conflicts of Interest:** The authors declare no conflict of interest.
