Patterned growth of organic semiconductors for ultra-high resolution microelectronics and optoelectronics

With intrinsic properties of flexibility, biocompatibility and lightweight, organic semiconductors have gained significant interests and witnessed substantial progresses in microelectronics and optoelectronics. Recently, the rapid development of wearable electronics such as near-eye displays requires the downscaling of the organic semiconductor devices to micrometers to provide immersive experiences and low power consumption. This review summarizes our work in patterned growth of organic semiconductors since 2007, with the aim of developing a photolithography compatible technology for ultra-high-resolution organic semiconductor devices. Upon deposition onto patterned surfaces, the organic molecules can be selectively grown on designated areas in three different mechanisms which are dependent on molecular chemical structure, deposition parameters, pre-pattern chemistry and dimensions. The three mechanisms, induced namely by binding energy difference, step-edges and surface molecular density modulation, can be rooted to initial nucleation of molecules, and analog to those in inorganic thin film growth at atomic scale. The patterned organic semiconductors can be engineered physically and dimensionally under various circumstances in vacuum, air, solution, or emulsion. Finally, employing these strategies, ultrahigh-resolution electronic and optoelectronic devices are demonstrated, and outlook of the further developments are discussed.