Super- and Ferroelastic Organic Semiconductors for Ultraflexible Single-Crystal Electronics.

Like silicon, single crystals of organic semiconductors are pursued to attain intrinsic charge transport properties. However, they are intolerant to mechanical deformation, impeding their application in flexible electronic devices. Such contradictory properties, namely exceptional molecular ordering and mechanical flexibility, are unified in this work. We found that bis(triisopropylsilylethynyl)pentacene (TIPS-P) crystals can undergo mechanically induced structural transitions to exhibit superelasticity and ferroelasticity. These properties arise from cooperative and correlated molecular displacements and rotations in response to mechanical stress. By utilizing a bending-induced ferroelastic transition of TIPS-P, flexible single-crystal electronic devices were obtained that can tolerate strains (ϵ) of more than 13 % while maintaining the charge carrier mobility of unstrained crystals (μ>0.7 μ0 ). Our work will pave the way for high-performance ultraflexible single-crystal organic electronics for sensors, memories, and robotic applications.