Overcoming Electrochemical Instabilities of Printed Silver Electrodes in All-Printed Ion Gel Gated Carbon Nanotube Thin-Film Transistors
Overcoming Electrochemical Instabilities of Printed Silver Electrodes in All-Printed Ion Gel Gated Carbon Nanotube Thin-Film Transistors
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DOI：
10.1021/acsami.9b14916
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发表时间：
2019-11-06
影响因子：
9.5
通讯作者：
Cui, Zheng
中科院分区：
文献类型：
--
作者：
Robin, Malo;Portilla, Luis;Cui, Zheng
银墨是在全印刷离子凝胶栅控晶体管的制造中用于印刷电极的最广泛使用的导电材料，因为其高导电性和低成本。然而，印刷银电极的电化学不稳定性通常是最大的问题之一，无论是在空气中银被氧化还是在潮湿环境中发生电化学迁移。尽管如此，迄今为止尚未研究印刷银电极在离子凝胶介质中的电化学稳定性。在这项工作中，我们研究了印刷银电极的电化学不稳定性，在完全印刷的离子凝胶门控单壁碳纳米管（SWCNT）薄膜晶体管（TFT），并制定了一些策略来克服这些问题。采用全印刷的基于离子凝胶的p型单壁碳纳米管TFT来研究电化学不稳定性对印刷的单壁碳纳米管TFT的电学行为的影响。结果表明，由于离子液体的腐蚀，印刷银在阳极和阴极极化时不稳定。此外，银源/漏电极的阳极腐蚀被证明是负责印刷单壁碳纳米管TFT的电故障在线性和饱和的制度。当防止印刷的银电极与离子凝胶直接接触时，这些问题得到了完全解决。例如，离子凝胶被部分地印刷在器件通道中以避免接触印刷的银源电极和漏电极。同时，银侧栅电极被喷墨印刷的PEDOT：PSS电极取代，以避免栅电极相关的不稳定性。因此，所制造的全印刷电化学稳定的SWCNT TFT具有更高的I-ON/I-OFF比（10（5）至10（6））、更小的亚阈值斜率（10（5）至10（6（类似于70 mV/dec），滞后较小（Delta V = 0.025 V），栅极电压为1.2至-0.5 V。此外，全印刷SWCNTTFT的极性从p沟道转换为双极性，同时实现较低的漏电流。
Silver ink is the most widely used conductive material for printing electrodes in the fabrication of all-printed ion gel gated transistors because of their high conductivity and low cost. However, electrochemical instability of printed silver electrodes is generally one of the biggest issues, whether it is in air where silver gets oxidized or in a moisture environment where electrochemical migration occurs. Notwithstanding, the electrochemical stability of printed silver electrodes in ion gel medium has not been studied so far. In this work, we studied the electrochemical instabilities of printed silver electrodes in fully printed ion gel gated single-walled carbon nanotube (SWCNT) thin-film transistors (TFTs) and developed some strategies to overcome these issues. All-printed ion gel-based p-type SWCNT TFTs were employed to investigate the impact of electrochemical instabilities on the electrical behavior of printed SWCNT TFTs. The results have demonstrated that printed silver was unstable at anodic and cathodic polarization because of the corrosion by the ionic liquid. Besides, anodic corrosion of silver source/drain electrodes was shown to be responsible for the electrical failure of printed SWCNT TFTs in both the linear and saturated regime. These issues were completely resolved when preventing printed silver electrodes from coming into direct contact with ion gels. For example, ion gels were partially printed in device channels to avoid contacting the printed silver source and drain electrodes. At the same time, silver side-gate electrodes were replaced by inkjet-printed PEDOT:PSS electrodes to avoid gate electrode-related instabilities. Consequently, all-printed electrochemically stable SWCNT TFTs fabricated were obtained with enhanced performance of higher I-ON/I-OFF ratios (10(5) to 10(6)), smaller subthreshold slopes (similar to 70 mV/dec), and smaller hysteresis (Delta V = 0.025 V) at gate voltages from 1.2 to -0.5 V. Additionally, the polarity of all-printed SWCNT TFTs was converted from the p-channel to ambipolar while achieving lower leakage currents.