Doping-Free Carbon-Nanotube Transistors as Wide-Temperature-Range Devices

With the development of fields such as lunar exploration and automotive technology, the importance of devices suitable for wide-temperature range is increasingly highlighted. Chemically doped devices, represented by silicon, hardly meet wide-temperature-range requirements, as impurities affect transistor operation at both low and high temperatures. Carbon nanotube (CNT) transistors have high- and low-temperature advantages due to their doping-free structure. In this study, we investigated operation in the temperature range of 10 to 473 K of both n- and p-type field-effect transistors based on network carbon nanotube thin film, complementing the research in wide-temperature-range transport characteristics of CNT transistors, and explored the mechanism of the devices. Experimental results demonstrate that compared to other structures, at high temperature, doping-free carbon nanotube field-effect transistors exhibit no intrinsic excitation induced device leakage, maintaining an on-off ratio of over 10³ even at 473 K. At low temperature, no carrier freeze-out issues are observed, resulting in a more stable threshold voltage. Those results explore the advantage of the doping-free device in the wide-temperature range scenario, being free from dopant that can affect performance at extreme temperatures, revealing the great potential of carbon-based devices for wide-temperature-range applications.