Ohmic-contact-gated carbon nanotube transistors

NU 2020-248

INVENTORS
William A. Gaviria Rojas
Megan E. Beck
Vinod K. Sangwan
Mark C. Hersam*

SHORT DESCRIPTION
Novel transistor architecture enabling high-gain analog amplification with flexible, semiconductors at scaled dimensions
 
BACKGROUND
Traditional transistors are produced with inflexible materials, which are incompatible with the demands of next-generation wearable electronics. Solution-processed carbon nanotubes are well positioned to address this need due to their mechanical flexibility and compatibility with low-cost additive manufacturing. However, to fully realize their potential in physiological sensing applications, circuit components must be manufactured with very small device dimensions. Unfortunately, transistors are now so small that unavoidable limitations due to the length scale of electrons moving through the semiconductor material are being encountered. These limitations, known as ”short channel effects” cause problems with performance and reliability of individual transistors and are a driving force behind the creation of new transistor architectures.

ABSTRACT
Northwestern researchers have developed an ohmic-contact-gated transistor (OCGT), which is a novel transistor architecture that enables excellent amplification of extremely weak physiological signals while being produced from flexible, solution processed carbon nanotubes. In comparison to other solution-processed semiconductor amplifiers, this technology can achieve the highest reported length-scaled signal gain (~230 µm-1) and the highest reported width-normalized output current (~30 µA·µm-1) to date. These transistors are manufactured with standard photolithography techniques to enable relatively low-cost, fast production. As the OCGT design is compatible with other semiconducting materials, this invention serves as a general pathway to high-performance, solution-processed analog electronics.

APPLICATIONS

  • Transistors
  • Solution-processed electronics
  • Analog amplifiers
  • Wearable physiological monitors

ADVANTAGES

  • Manufactured with standard photolithography techniques
  • Compatibility with flexible substrates
  • Greater stability than organic thin-film transistors
  • Outperforms competing technologies with respect to the current density needed

PUBLICATION
Gaviria Rojas W, Beck M, Sangwan V, GuoS and Hersam M (2021) Ohmic-Contact-Gated Carbon Nanotube Transistors for High-Performance Analog AmplifiersAdvanced Materials
 
IP STATUS
A provisional application has been filed.

Patent Information: