Control Over Molecular Architectures of Carbohydrate-based Block Copolymers for Stretchable Electrical Memory Devices
C.-C. Hung, S. Nakahira, Y.-C. Chiu, T. Isono, H.-C. Wu, K. Watanabe, Y.-C. Chiang, S. Takashima, R. Borsali, S.-H. Tung*, T. Satoh*, and W.-C. Chen*
2018/10/01
We synthesized a series of new intrinsically stretchable block copolymers (BCPs) in linear AB-type, ABA-type, and star-shaped architectures composed of oligosaccharide (MH) and flexible poly(n-butyl acrylate) (PBA) blocks for the application in field-effect transistor memory. The BCP thin films are used as the charge trapping layers in the memory devices where the BCPs phase separate into ordered MH microdomains in soft PBA matrices. The MH microdomain works as the charge-trapping sites while the soft PBA matrix provides a stretchability. In particular, the BCPs of the ABA-type and star-shaped architectures with the end MH blocks not only show superior memory performances but also form physical networks that impart mechanical resilience to the thin films such that they can endure 100% strain without formation of cracks. The mobilities and the memory windows of the devices are nearly constant even when the charge trapping layers are stretched and released at 50% strain for 1000 cycles. This work highlights the importance of the molecular architectures on the BCPs intended for stretchable electronic materials.
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