Yu Min, Wan Haochuan, Cai Le, Miao Jinshui, Zhang Suoming, Wang Chuan
Electrical and Computer Engineering , Michigan State University , East Lansing , Michigan 48824 , United States.
National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Key Laboratory of Microelectronic Devices and Circuits (MOE), Institute of Microelectronics , Peking University , Beijing 100871 , China.
ACS Nano. 2018 Nov 27;12(11):11572-11578. doi: 10.1021/acsnano.8b06748. Epub 2018 Nov 5.
Semiconducting single-wall carbon nanotubes (sSWCNTs) have been widely used as the channel material for high-performance printed flexible thin-film transistors (TFTs). Due to the absorption of moisture and oxygen in air, the printed sSWCNT TFTs generally exhibit p-type characteristics only. In this paper, we report fully printed dual-gate sSWCNT TFTs that exhibit almost symmetric ambipolar characteristics. With the applied control gate voltage varying from -60 to +60 V, a threshold voltage tuning range of 27 V is achieved, allowing the device to be effectively tuned into either predominantly p-type or predominantly n-type. The tunable ambipolar characteristics are found to be very stable over a long period of time (4 months). By integrating two printed dual-gate TFTs biased with different control gate voltages, a complementary metal oxide semiconductor inverter with close to rail-to-rail output voltage swing is demonstrated. The use of a dual-gate structure for achieving n-type printed carbon nanotube TFTs is much more controllable and repeatable compared to other methods such as chemical doping. Our work shows the feasibility of implementing more sophisticated complementary logic circuits using printed flexible carbon nanotube transistors.
半导体单壁碳纳米管（sSWCNTs）已被广泛用作高性能印刷柔性薄膜晶体管（TFTs）的沟道材料。由于空气中水分和氧气的吸附作用，印刷的sSWCNT TFTs通常仅表现出p型特性。在本文中，我们报道了全印刷双栅sSWCNT TFTs，其表现出几乎对称的双极性特性。随着施加的控制栅极电压在-60至+60 V之间变化，实现了27 V的阈值电压调谐范围，使得该器件能够有效地调谐为主要是p型或主要是n型。发现可调节的双极性特性在很长一段时间（4个月）内非常稳定。通过集成两个由不同控制栅极电压偏置的印刷双栅TFT，展示了一种具有接近轨到轨输出电压摆幅的互补金属氧化物半导体反相器。与诸如化学掺杂等其他方法相比，使用双栅结构来实现n型印刷碳纳米管TFTs更具可控性和可重复性。我们的工作表明了使用印刷柔性碳纳米管晶体管实现更复杂的互补逻辑电路的可行性。
