Rubrene crystal field-effect mobility modulation via conducting channel wrinkling

With the impending surge of flexible organic electronic technologies, it has become essential to understand how mechanical deformation affects the electrical performance of organic thin-film devices. Organic single crystals are ideal for the systematic study of strain effects on electrical properties without being concerned about grain boundaries and other defects. Here we investigate how the deformation affects the field-effect mobility of single crystals of the benchmark semiconductor rubrene. The wrinkling instability is used to apply local strains of different magnitudes along the conducting channel in field-effect transistors. We discover that the mobility changes as dictated by the net strain at the dielectric/semiconductor interface. We propose a model based on the plate bending theory to quantify the net strain in wrinkled transistors and predict the change in mobility. These contributions represent a significant step forward in structure–function relationships in organic semiconductors, critical for the development of the next generation of flexible electronic devices. Building flexible electronic devices demands an understanding of how mechanical deformation affects the active materials. Here, the authors observe and quantify the effects of local strains generated by the wrinkling instability in the conducting channel of rubrene crystal thin-film transistors.