Institute of Optoelectronic Display, National & Local United Engineering Lab of Flat Panel Display Technology, Fuzhou University, Fuzhou 350002, China.
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350100, China.
ACS Appl Mater Interfaces. 2020 Nov 4;12(44):49915-49925. doi: 10.1021/acsami.0c15553. Epub 2020 Oct 21.
Organic electrochemical transistors (OECTs) have attracted considerable interests for various applications ranging from biosensors to digital logic circuits and artificial synapses. However, the majority of reported OECTs utilize large channel length up to several or several tens of micrometers, which limits the device performance and leads to low transistor densities. Here, we demonstrate a new design of vertical OECT architecture with a nanoscale channel length down to ∼100 nm. The devices exhibit a high on-state current of over 20 mA under a low bias voltage of 0.5 V, a fast transient response of less than 300 μs, and an extraordinary transconductance up to 68.88 mS, representing a record-high value for OECTs. The excellent electrical performance is attributed to the novel structure with a nanoscale channel length defined by the channel material thickness, which is intrinsically different from that of conventional OECTs with the channel length limited by the lithography resolution. Owing to the low thermal budget, we fabricate flexible devices on a flexible substrate, which exhibit unprecedented endurance characteristics and mechanical robustness after 1000 blending cycles. Furthermore, the proposed device is capable of mimicking biological inhibitory synapses for application in intelligent artificial neural networks. Our work not only pushes the performance limit of OECTs but also opens up a new design of OECTs for high-performance biosensors, digital logic, and neuromorphic devices.
有机电化学晶体管 (OECT) 因其在从生物传感器到数字逻辑电路和人工突触等各种应用中的广泛应用而受到极大关注。然而,大多数报道的 OECT 采用几微米到几十微米的大沟道长度,这限制了器件性能并导致低晶体管密度。在这里,我们展示了一种具有纳米级沟道长度低至约 100nm 的新型垂直 OECT 架构设计。该器件在 0.5V 的低偏置电压下表现出超过 20mA 的高导通电流、小于 300μs 的快速瞬态响应和高达 68.88mS 的非凡跨导,代表了 OECT 的创纪录值。优异的电性能归因于具有纳米级沟道长度的新型结构,该结构由沟道材料厚度定义,与通道长度受光刻分辨率限制的传统 OECT 有本质区别。由于低热预算,我们在柔性衬底上制造了柔性器件,在经过 1000 次混合循环后,它们表现出前所未有的耐用性和机械鲁棒性。此外,所提出的器件能够模拟生物抑制突触,可用于智能人工神经网络。我们的工作不仅推动了 OECT 的性能极限,还为高性能生物传感器、数字逻辑和神经形态器件开辟了 OECT 的新设计。