Transparent conductive materials (TCM) comprise materials in a group that combine the mutually exclusive properties of transparency (effective transmission of light) and electrical conductivity; these characteristics can be jointly achieved on processing the materials as thin films on transparent substrates.

The history of TCM begins with a report of a transparent and electrically conductive film of cadmium oxide by Karl Bädeker (Bädeker, K. (1907). Ann. Phys. 22: 749). Since that time, material scientists and engineers have devoted much research effort to find new materials – mainly transparent conductive oxides (TCOs) – such as tin oxide (SnO₂, between 1930 and 1950), indium‐doped tin oxide (patent of Corning Company, circa 1951), and zinc oxide. Subsequently, other electrically conductive inorganic oxides have been discovered and applied to produce TCM films, for example, aluminum‐doped zinc oxide and fluorine‐doped tin oxide. At present, TCO materials have attained a dominant status in the TCM field, but this domain has broadened with conductive organic polymers, such as polypyrrole and their derivatives, metal nanowire networks, and two‐dimensional materials such as graphene. Several techniques to deposit thin films onto various substrates have been developed, some of which have transcended the laboratory to an industrial scale, achieving commercial potential through mass production. TCM have found abundant applications in several technical fields, but the principal factor that has fueled the research on TCM syntheses and their processing is undoubtedly the development of optoelectronic materials and devices in which the principles of actuation involve an application of electric current or voltage to control the emission or passage of light; the ubiquitous examples are display devices (television, computer, telephone screens). Nevertheless, other applications that require TCM, such as smart windows (based on electrochromic or liquid crystalline materials) and systems for harvesting solar energy, have attained enormous relevance in the present context of seeking energy efficiency and clean energies, triggering even more the scientific and technical developments in TCM, as reflected in the intensive and continuing research in this field.

Transparent conducting films are estimated to become a market of value of US$1.2 billion in 2025; intensive research is hence important to discover superior materials, new substrates, and new ways to enhance light transmission, to increase the surface conductivity, to add flexibility, and to decrease costs. We trust that our effort in editing a book presenting the state of the art about transparent conducting materials will contribute to this progress as an effective reference for TCM developers and users. This book covers current information about the principal aspects concerning TCM, ranging from the basic aspects of solid‐state physics and chemistry to cutting‐edge applications, passing through synthesis, techniques to deposit thin films, to their characterization, and future perspectives.