Optoelectronics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE, UK.
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, P. R. China.
Adv Mater. 2017 Jun;29(23). doi: 10.1002/adma.201606938. Epub 2017 Apr 11.
Solution-processed semiconductors such as conjugated polymers have great potential in large-area electronics. While extremely appealing due to their low-temperature and high-throughput deposition methods, their integration in high-performance circuits has been difficult. An important remaining challenge is the achievement of low-voltage circuit operation. The present study focuses on state-of-the-art polymer thin-film transistors based on poly(indacenodithiophene-benzothiadiazole) and shows that the general paradigm for low-voltage operation via an enhanced gate-to-channel capacitive coupling is unable to deliver high-performance device behavior. The order-of-magnitude longitudinal-field reduction demanded by low-voltage operation plays a fundamental role, enabling bulk trapping and leading to compromised contact properties. A trap-reduction technique based on small molecule additives, however, is capable of overcoming this effect, allowing low-voltage high-mobility operation. This approach is readily applicable to low-voltage circuit integration, as this work exemplifies by demonstrating high-performance analog differential amplifiers operating at a battery-compatible power supply voltage of 5 V with power dissipation of 11 µW, and attaining a voltage gain above 60 dB at a power supply voltage below 8 V. These findings constitute an important milestone in realizing low-voltage polymer transistors for solution-based analog electronics that meets performance and power-dissipation requirements for a range of battery-powered smart-sensing applications.
溶液处理的半导体，如共轭聚合物，在大面积电子学中有很大的潜力。虽然由于其低温和高通量的沉积方法非常有吸引力，但它们在高性能电路中的集成一直很困难。一个重要的遗留挑战是实现低电压电路操作。本研究集中在基于聚（茚并二噻吩-苯并噻二唑）的最先进的聚合物薄膜晶体管上，并表明通过增强栅极到通道电容耦合实现低电压操作的一般范例无法实现高性能器件行为。低电压操作所需的数量级纵向场降低起着根本性的作用，使体陷阱成为可能，并导致接触性能下降。然而，基于小分子添加剂的陷阱减少技术能够克服这种效应，从而实现低电压高迁移率操作。这种方法很容易适用于低电压电路集成，正如这项工作所证明的那样，它演示了高性能模拟差分放大器，在 5 V 的电池兼容电源电压下工作，功耗为 11 µW，并在低于 8 V 的电源电压下获得超过 60 dB 的电压增益。这些发现构成了实现用于溶液基模拟电子学的低电压聚合物晶体管的重要里程碑，满足了一系列电池供电智能传感器应用的性能和功耗要求。
