Zhou Jianshuo, Liu Lijun, Shi Huiwen, Zhu Maguang, Cheng Xiaohan, Ren Li, Ding Li, Peng Lian-Mao, Zhang Zhiyong
Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-Based Electronics, Department of Electronics, Peking University, Beijing 100871, China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
ACS Appl Mater Interfaces. 2021 Aug 11;13(31):37475-37482. doi: 10.1021/acsami.1c07782. Epub 2021 Aug 2.
Owing to the combination of high carrier mobility and saturation velocity, low intrinsic capacitance, and excellent stability, the carbon nanotube (CNT) has been considered as a perfect semiconductor to construct radio frequency (RF) field-effect transistors (FETs) and circuits with an ultrahigh frequency band. However, the reported CNT RF FETs usually exhibited poor real performance indicated by the as-measured maximum oscillation frequency (), and then the amplifiers, which are the most important and fundamental RF circuits, suffered from a low power gain and a low frequency band. In this work, we build RF transistors on solution-derived randomly orientated CNT films with improved quality and uniformity. The randomly orientated CNT film FETs exhibit the record as-measured maximum of 90 GHz, demonstrating the potential for over 28 GHz (at least one-third of 90 GHz) 5G mmWave (frequency range 2) applications. Benefiting from the large-scale uniformity of CNT films, FETs are designed and fabricated with a large channel width to present low internal resistance for the standard 50 Ω impedance matching guide line, which is critical to construct an RF amplifier. Furthermore, we first demonstrate amplifiers with a maximum power gain up to 11 dB and output third-order intercept point (OIP3) of 15 dBm, both at the K-band, which represents the record of a CNT amplifier and is even comparable with a commercial amplifier based on III-V RF transistors.
由于具有高载流子迁移率和饱和速度、低本征电容以及出色的稳定性，碳纳米管（CNT）被视为构建具有超高频段的射频（RF）场效应晶体管（FET）和电路的理想半导体。然而，报道的碳纳米管射频场效应晶体管通常表现出较差的实际性能，如测量得到的最大振荡频率（）所示，进而作为最重要且最基本的射频电路的放大器，存在功率增益低和频段低的问题。在这项工作中，我们在溶液衍生的具有改进质量和均匀性的随机取向碳纳米管薄膜上构建射频晶体管。随机取向的碳纳米管薄膜场效应晶体管展示出测量得到的创纪录的90 GHz最大振荡频率，证明了其在超过28 GHz（至少为90 GHz的三分之一）的5G毫米波（频段2）应用中的潜力。受益于碳纳米管薄膜的大规模均匀性，设计并制造了具有大沟道宽度的场效应晶体管，以呈现低内阻，用于标准的50Ω阻抗匹配导线，这对于构建射频放大器至关重要。此外，我们首次展示了在K波段最大功率增益高达11 dB且输出三阶截点（OIP3）为15 dBm的放大器，这代表了碳纳米管放大器的记录，甚至可与基于III - V族射频晶体管的商业放大器相媲美。
