N2200 based organic rectifying diodes for ambient electromagnetic energy harvesting

Rectifying diodes are key components for electromagnetic energy-harvesting systems. Recently, organic diode have attract a lot of attention for this applications due to its low-cost, flexibily and easy disposability In this work, we report the fabrication and electrical characterization of n-type organic diodes based on Polyera N2200 with Au/N200/Al configuration The reference devices exhibit a clear rectifying behavior with rectification ratios of ∼10 ³ at ±3 V, but show pronounced hysteresis attributed to charge trapping and detrapping at the metal–semiconductor interfaces. A second important result concerns the impact of the gold surface functionalization prior to polymer deposition. This treatment increases the electron injection barrier at the gold/N2200 interface and enhances the molecular ordering of N2200 near the contact region. As a consequence, the current-voltage response becomes more stable and reproducible. In particular, PFBT-treated devices exhibit rectification ratios exceeding 10⁴ at ±3 V, reduced leakage current, and strongly suppressed hysteresis compared with untreated devices. These improvements are attributed to improved charge injection at the metal/semoiconductor interface, as supported by UPS and contact-angle measurements. The electrical characteristics were reproducible across multiple devices and remained stable over repeated voltage sweeps. These results demonstrate that interface engineering plays an important role in the performance and stability of N2200-based diode rectifiers. Overall, the demonstrated performance highlights the potential of these devices for RF-to-DC conversion and flexible rectenna applications operating in the MHz–GHz frequency range.