Phase segregation controlled semiconductor crystallization for organic thin film transistors

In this article, we provide an in-depth review of important works on phase segregation which occurs as a result of mixing organic semiconductors with polymeric additives. Throughout the discussion, the indispensable correlations among phase segregation, crystal growth, layer structure and film morphology are showcased using specific examples that mainly entail small-molecule organic semiconductors such as 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) and 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT). The various factors that impact the phase segregation are analyzed, which include surface energy, solvent choice, additive nature, and substrate interaction. The beneficial effects of phase segregation on charge transport and operational stabilities of organic semiconductor based organic thin film transistors (OTFTs) are also assessed. We believe that the phase segregation examples discussed in this work shed light on optimizing the electrical performance of organic semiconductors and unlock favorable features useful for their application in high-performance organic electronics on flexible substrates.