Organic diode rectifier have attracted a lot of attention recently for RF energy harvesting, and much effort has been applied toward extending the ultra-high frequency range [1-2]. An important parameter that should be considered for diodes used in RF rectifier is the turn on voltage, which should be low to overcome the problem of the low voltage generated and power extracted from energy harvesting.
In this work, we focused on pentacene organic rectifier with high rectification ratio and low threshold voltage obtained by tuning the work function of gold with a self-assembled monolayer of PFBT and optimizing the thickness of the organic layer. We demonstrate a high rectification ratio up to 107 and a very low turn on voltage as low as 20 mV. Flexible rectifier diode have been also fabricated in release paper WO84, high rectification ratio of 106 was obtained even after bending of the device. The pentacene based rectifier diodes were also demonstrated to operate at more than 1GHz. This provides a great potential for fabricating high-performance organic flexible diodes and opens the way for the development of high frequency response using organic materials.
 D. Im et al, adv. Mater. 23, 644-648 (2011).
 C-mo. Kang et al, adv. Electron. Mater. 2, 1500282 (2016).