Transparent conductors (TCs) are electrically conductive and optically transparent materials used in various applications. They are made from materials such as semiconducting oxides (e.g., tin, indium, zinc, cadmium) and metals (e.g., silver, gold, titanium nitride). The figure of merit for TCs is defined as the ratio of electrical conductivity to optical absorption coefficient. Fluorine-doped zinc oxide and cadmium stannate have the highest figures of merit. Other factors influencing the choice of TC include physical, chemical, thermal durability, etchability, conductivity, plasma wavelength, work function, thickness, deposition temperature, uniformity, toxicity, and cost. TCs have a wide range of applications, including energy-conserving windows (low-e windows), oven windows, solar cells, flat-panel displays, smart windows, vehicle defrosting, xerographic copiers, and touch-control panels. Different TCs are best suited for different applications, and the choice depends on the specific requirements of the application. The preparation methods of TCs include physical methods (sputtering, evaporation, pulsed laser deposition) and chemical methods (chemical vapor deposition, sol-gel, chemical bath deposition, electroplating). Spray pyrolysis was first used commercially for depositing conductive tin oxide films, while chemical vapor deposition is widely used for producing fluorine-doped tin oxide films. Sputtering is preferred for indium tin oxide (ITO), which is mainly used in flat-panel displays. Conductive zinc oxide films are being investigated for potential use in photovoltaics and display applications due to their lower cost and easier etchability. The performance of TCs is evaluated based on their electrical conductivity and optical absorption. The figure of merit (σ/α) is a quantitative measure of TC performance. Fluorine-doped zinc oxide and cadmium stannate have the best figures of merit. Theoretical models suggest that the figure of merit is influenced by the mobility and effective mass of conduction electrons. The maximum mobility is limited by various scattering mechanisms, and the best TC films have mobilities in the range of 50–60 cm²/V·s, closely approaching the theoretical upper limit.Transparent conductors (TCs) are electrically conductive and optically transparent materials used in various applications. They are made from materials such as semiconducting oxides (e.g., tin, indium, zinc, cadmium) and metals (e.g., silver, gold, titanium nitride). The figure of merit for TCs is defined as the ratio of electrical conductivity to optical absorption coefficient. Fluorine-doped zinc oxide and cadmium stannate have the highest figures of merit. Other factors influencing the choice of TC include physical, chemical, thermal durability, etchability, conductivity, plasma wavelength, work function, thickness, deposition temperature, uniformity, toxicity, and cost. TCs have a wide range of applications, including energy-conserving windows (low-e windows), oven windows, solar cells, flat-panel displays, smart windows, vehicle defrosting, xerographic copiers, and touch-control panels. Different TCs are best suited for different applications, and the choice depends on the specific requirements of the application. The preparation methods of TCs include physical methods (sputtering, evaporation, pulsed laser deposition) and chemical methods (chemical vapor deposition, sol-gel, chemical bath deposition, electroplating). Spray pyrolysis was first used commercially for depositing conductive tin oxide films, while chemical vapor deposition is widely used for producing fluorine-doped tin oxide films. Sputtering is preferred for indium tin oxide (ITO), which is mainly used in flat-panel displays. Conductive zinc oxide films are being investigated for potential use in photovoltaics and display applications due to their lower cost and easier etchability. The performance of TCs is evaluated based on their electrical conductivity and optical absorption. The figure of merit (σ/α) is a quantitative measure of TC performance. Fluorine-doped zinc oxide and cadmium stannate have the best figures of merit. Theoretical models suggest that the figure of merit is influenced by the mobility and effective mass of conduction electrons. The maximum mobility is limited by various scattering mechanisms, and the best TC films have mobilities in the range of 50–60 cm²/V·s, closely approaching the theoretical upper limit.