High-frequency polymer diode rectifiers for flexible wireless power-transmission sheets

Abstract

In this work, we successfully implemented flexible high-frequency rectifying diodes on polycarbonate substrates using the polythiophene-based semiconducting polymers. We show that the appropriate conductivity of the intermediate hole-injection layer PED-OT: PSS between the anode and the semiconducting polymer is critical to simultaneously achieve enhanced forward currents and rectification ratios. Among the semiconducting polymers studied (P3HT and PQT-12), the diodes based on carefully purified PQT-12 exhibited higher forward currents, higher rectification ratios, much better environmental stability, and much higher operation frequencies. A forward current density up to similar to 6 A/cm(2) at 5 V, a rectification ratio up to 2 x 10(4) at +/- 5V, and an operation frequency of the diode rectifier over 14 MHz were achieved with the PQT-12 rectifying diodes. To demonstrate the use of the high-speed polymer rectifying diodes in wireless power transmission, we integrate the polymer-based vertical Schottky diode rectifier, printed antenna and capacitors on plastic substrates to demonstrate a flexible wireless power-transmission sheet that can convert a 13.56 MHz electromagnetic wave into the dc power to drive load devices. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.