Organic Donor/Acceptor Heterostructures Based Diode Rectifier: Hybrid Film Fabrication and Integration on Flexible Substrate

ABSTRACT The need for cost‐effective and high‐frequency rectifier has prompted researchers to explore organic semiconductors and their suitable heterostructures. Here, we demonstrate an organic donor/acceptor (D/A) heterostructure‐based diode rectifier fabricated with thin films of Copper phthalocyanine/7,7,8,8‐Tetracyanoquinodimethane (CuPc/TCNQ). The D/A materials were deposited in a hybrid way; with CuPc film being deposited by solution processing, while TCNQ film was thermally evaporated under vacuum conditions. The diode exhibited excellent electrical stability, reproducibility, and achieved a rectification ratio (RR) greater than 10 3 at 1.2 V. A low threshold voltage ca. 0.4 V and an ideality factor of 2.3 could be achieved from the diode characteristics. Moreover, with the variation in thickness of TCNQ film, the electrical characteristics of the diode changed drastically, offering a good way to enabling fine‐tuning of device characteristics, including, turn‐on voltage, leakage current, and overall rectification efficiency. An optimum film thickness of TCNQ (320 nm) with fixed CuPc film thickness (330 nm) has been identified for best device performances. The device produced a steady DC response under varying sinusoidal pulses with a frequency response about 1 MHz, making it suitable for radio frequency identification (RFID) applications. Additionally, CuPC/TCNQ heterostructure was integrated on flexible substrate for promising diode characteristics.