The fields of optoelectronics have opened up new ways to make technologies that are very important in today’s world. From the atomic level to the development of an optical system, research has gone from being very basic to very advanced. A lot of people are interested in metal oxides (MOs) like ITO (Indium Tin Oxide), zinc oxide (ZnO), and barium oxide (BaO) based nanomaterials because they have unique qualities and could be explored in optoelectronics devices like solar cells, OLEDs, flat-panel displays, and flexible transparent electronics. In terms of thin-film production, optoelectronic properties, electronic structure, defect states, charge transport methods, and materials design principles, MOs semiconductors are very distinct from inorganic semiconductors like silicon and III-V compounds. MOs are different from other unusual electronic materials. This chapter talks about how they are unique and how they are the same with respect to their physicochemical properties, electrical properties, thin-film production techniques, and their specific uses in solar cells and thin-film transistors.