Rectification Enhancement in Organic Semiconductors: Study of Channel Structure and Electrode Design

Solution-processable materials such as conjugated polymers are considered promising candidates for next-generation electronic devices due to their compatibility with low-cost, large-area, and flexible fabrication techniques. However, polymer-based electronic devices often suffer from inherently low electrical performance, which remains a significant challenge.In this study, we present a simple and effective patterning method using a polydimethylsiloxane (PDMS) mold to fabricate highly aligned nanostructure channel devices based on conjugated polymers poly(diketopyrrolopyrrole-alt-thieno[3,2-b]thiophene) (DPP-DTT). In nanopatterned conjugated polymers, the alignment of molecular chains enables charge carriers to move efficiently and rapidly along the direction of the chains. Nanoscale channel structures induce field enhancement effects at the interface. This effect reduces the Schottky barrier height at the metal-semiconductor interface. Furthermore, by adopting an asymmetric electrode configuration with gold (Au) and aluminum (Al), we implement bandgap engineering through controlled energy level alignment to modulate hole and electron injection behaviors. Consequently, by controlling the factors, the rectification characteristics of nanostructure channel diode devices based on conjugated polymers were improved.