Abstract
Transparent electronics has gained tremendous attention in recent years because of the growing demand for see-through devices in applications such as displays, windscreens, and wearables. These applications require transparent electronics in a large area and flexible form factors along with performances at par with conventional electronics. Additionally, the controlled transience and degradability of electronics are desired to reduce the end-of-life challenges. Attaining these attributes simultaneously is challenging as inherent material properties do not always align well, and there are technological limitations such as thermal budget issues in the case of flexible substrates. As a result, several materials and structures, including 1D nanowires, 2D nanosheets, metal oxides, and polymers etc., are explored. This comprehensive review discusses these developments related to transparent electronics as well as the challenges associated with the development of flexible and transient transparent electronics over large areas. Potential solutions to overcome these challenges and various resource-efficient deposition and printing technologies are also presented along with examples of reported transparent circuits, sensors, actuators, and energy devices. Finally, potential future directions are discussed for flexible transient transparent electronics as their ever-growing demand could lead to the emergence of new materials, fabrication techniques, and applications.