Low-voltage high-performance flexible digital and analog circuits based on ultrahigh-purity semiconducting carbon nanotubes

Ray Beausoleil,Ting Lei,Gregory Pitner,Guanhua Fang,Lei-Lai Shao,Chenxin Zhu,Kwang-Ting Cheng,Sicheng Li,Tsung-Ching Huang,Zhenan Bao,Yu-Qing Zheng,H.-S Philip Wong

doi:10.1038/s41467-019-10145-9

Abstract

Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for flexible and wearable electronics. However, it usually suffers from low semiconducting tube purity, low device yield, and the mismatch between p- and n-type TFTs. Here, we report low-voltage and high-performance digital and analog CNT TFT circuits based on high-yield (19.9%) and ultrahigh purity (99.997%) polymer-sorted semiconducting CNTs. Using high-uniformity deposition and pseudo-CMOS design, we demonstrated CNT TFTs with good uniformity and high performance at low operation voltage of 3 V. We tested forty-four 2-µm channel 5-stage ring oscillators on the same flexible substrate (1,056 TFTs). All worked as expected with gate delays of 42.7 ± 13.1 ns. With these high-performance TFTs, we demonstrated 8-stage shift registers running at 50 kHz and the first tunable-gain amplifier with 1,000 gain at 20 kHz. These results show great potentials of using solution-processed CNT TFTs for large-scale flexible electronics.

Highlights

Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for flexible and wearable electronics
With the pseudo-complementary metal oxide semiconductor (CMOS) design style[24,25], we demonstrate high-performance five-stage pseudo-CMOS-based ring oscillators running up to 3.5 MHz, an eight-stage shift register consisting of 304 CNT TFTs operating at 50 kHz, as well as a tunable-gain amplifier with 1000 voltage gain at 20 kHz26
Recent studies have shown that the selectivity of semiconducting single-walled CNTs (s-SWNTs) can be as high as 99.9%9,19,21,27

Summary

Introduction

Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for flexible and wearable electronics. To the best of our knowledge, these values are among the highest performance and the best uniformity for wafer-scale-fabricated flexible CNT TFTs (Supplementary Tables 1 and 2)[10].

Results

Conclusion