All-printed organic photodetectors with metal electrodes enabled by one-step solvent-mediated transfer printing technology

Abstract

A one-step solvent-mediated transfer printing technology (sTPT) is proposed to fabricate printable silver (Ag) electrodes. This simple approach can realize the residuals in the active layer serving as the mediator due to the capillary action without the use of any additional solvent. The as-cast polydimethylsiloxane (PDMS) was used as the stamp in the fabrication process. The residual solvent and the as-cast PDMS stamps simplified the fabrication process, while the transfer-printed Ag electrodes presented favorable conductivity and improved hydrophobicity due to the presence of residual PDMS on the surface of Ag, indicating the superiority as the top electrode for organic photodetectors (OPDs). Compared to the devices with the top Ag electrodes fabricated by the conventional evaporation method, we demonstrated that the OPDs with transfer-printed Ag electrodes presented better performance than that of the reference devices, including suppressed dark current, enlarged linear dynamic range, shortened response time, and optimized durability. These improved performances can be attributed to the fewer traps at the interface between the active layer and Ag electrodes. The sTPT may be a promising method for the fabrication of OPDs owing to the simplified fabrication process and enhanced device performance.