Carbon nanotube MOSFETs that operate beyond 1 THz, promising ultra-fast wireless communication, high-speed computing, and next-gen radar systems.
Researchers at Peking University, Xiangtan University, and Zhejiang University have developed a new generation of carbon nanotube (CNT)-based MOSFETs capable of operating at terahertz (THz) frequencies, pushing transistor performance far beyond conventional silicon limits. These devices could pave the way for ultra-fast wireless communication, high-speed computing, and next-generation radar systems.
Traditional silicon transistors max out at 100–300 GHz, sufficient for current wireless and computing applications but limiting for emerging 6G technologies. The newly developed CNT-based MOSFETs surpass 1 THz, enabling signal switching and amplification more than a trillion times per second. This leap in speed positions them as key components for future high-frequency electronics.
CNTs—cylindrical nanostructures of carbon atoms arranged in a hexagonal lattice—are prized for their exceptional electrical conductivity and mechanical robustness. By aligning films of semiconducting CNTs, the research team fabricated MOSFETs that combine high carrier mobility with impressive on-state current and transconductance. Optimized gate structures, including innovative Y-shaped gates, produced devices with gate lengths as short as 35–80 nm, achieving cut-off frequencies up to 551 GHz and maximum oscillation frequencies beyond 1 THz.
The team also demonstrated practical applications by creating millimeter-wave (mmWave) radio-frequency amplifiers using CNT MOSFETs. These amplifiers, operating at 30 GHz, delivered gains exceeding 21 dB, reliably boosting signal strength by over a hundredfold. Such performance highlights the potential of CNT arrays not only for digital circuits but also for THz analog systems, including ultra-fast wireless transmitters and receivers.
The research demonstrates how careful material alignment, gate engineering, and fabrication refinements can transform CNT MOSFETs from experimental devices into high-performance components ready for next-generation electronics. Future work could extend their use into THz sensing, high-speed data links, and advanced radar systems, potentially redefining the speed and efficiency of electronic communications.
“Aligned carbon nanotube films could serve as the backbone for both digital integrated circuits and terahertz analog devices,” the authors noted, emphasizing that their approach overcomes frequency limitations seen in earlier CNT transistor designs.
