Remarkably low flicker noise in solution-processed organic single crystal transistors

Shun Watanabe,Hirotaka Sugawara,Toshihiro Okamoto,Akifumi Yamamura,Jun Takeya,Balthasar Blülle,Roger Häusermann

doi:10.1038/s42005-018-0037-0

Abstract

Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit. Investigation of the noise in organic field-effect transistors is now sharing the spotlight with development of printed integrated circuits. The recent improvement of field-effect mobility (up to 15 cm2 V−1 s−1) has allowed for organic integrated circuits with a relatively high-speed operation (~50 kHz). Therefore, an in-depth understanding of the noise feature will be indispensable to further improve the circuit stability and durability. Here we performed noise measurements in solution-processed organic single crystal transistors, and discovered that a low trap density-of-states due to the absence of structural disorder in combination with coherent band-like transport gives rise to an unprecedentedly low flicker noise. The excellent noise property in organic single crystals will allow their potential to be fully exploited for high-speed communication and sensing applications.

Highlights

Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit
The cutoff frequency of the best performing organic field-effect transistor (OFET) approaches 30 MHz8, and operation frequencies of organic integrated circuits are on the order of 0.1–1 MHz4,14
We demonstrate noise measurements with wide frequency bands up to 1 MHz in an ideal, single crystal organic semiconductor

Summary

Introduction

Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit. Recent investigations of the 1/f noise in organic field- effect transistors based on π-conjugated polymers[17,18,19], amorphous or polycrystalline small molecules[20,21,22,23,24,25,26] were mainly focusing on device degradation under ambient and/or irradiated conditions, and on the contact resistance effect. These organic compounds typically have unavoidable structural disorder and their mobility is not sufficient for high-speed circuit operation. Thanks to its low trap density-of-states (DOS), and the coherent (band-like) transport nature, the amplitude of 1/f is found to be remarkably low, comparable to solution-processable, inorganic oxide semiconductors

Methods

Results

Conclusion