Tuning the Transconductance of Organic Electrochemical Transistors
Tuning the Transconductance of Organic Electrochemical Transistors
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DOI：
10.1002/adfm.202004939
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发表时间：
2020-10-06
影响因子：
19
通讯作者：
Lussem, Bjorn
中科院分区：
文献类型：
--
作者：
Paudel, Pushpa R.;Kaphle, Vikash;Lussem, Bjorn
有机电化学晶体管(OECTS)在非常低的电压下工作，将离子转化为电子信号，并达到极大的跨导值，使它们非常适合生物传感应用。然而，尽管它们有很好的性能，但它们的最大跨导与器件几何形状和外加电压的关系并不能被当前的电容器件模型正确地捕捉到。在这里，根据最近开发的2D器件模型对当前的定标定律进行了修正，该模型充分考虑了离子在聚合物通道内的漂移和扩散。结果表明，器件的最大跨导出现在晶体管的耗尽区和累积区之间的过渡区，这也解释了观察到的跨导峰随几何尺寸和漏极电势的移动。总体而言，研究结果有助于更好地理解OECTS的工作机制，并为进一步优化OCTS性能提供设计依据。
Organic electrochemical transistors (OECTs) operate at very low voltages, transduce ions into electronic signals, and reach extremely large transconductance values, making them ideally suited for bio-sensing applications. However, despite their promising performance, the dependence of their maximum transconductance on device geometry and applied voltages are not correctly captured by current capacitive device models. Here, current scaling laws are revised in the light of a recently developed 2D device model that adequately accounts for drift and diffusion of ions inside the polymer channel. It is shown that the maximum transconductance of the devices is found at the transition between the depletion and accumulation region of the transistors, which as well provides an explanation for the observed shift of the transconductance peak with geometric dimensions and the drain potential. Overall, the results provide a better understanding of the working mechanisms of OECTs, and facilitate design rules to optimize OECT performance further.