Department of Energy and Materials Engineering, Dongguk University, 26 Pil-dong, 3-ga, Jung-gu, Seoul, 100-715, Republic of Korea.
Key Laboratory of Polar Materials and Devices (Ministry of Education), Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), East China Normal University, Shanghai, 200241, China.
Adv Mater. 2017 Nov;29(41). doi: 10.1002/adma.201702729. Epub 2017 Aug 28.
Conjugated polymers came to an unprecedented epoch that the charge transport is limited only by small disorder within aggregated domains. Accurate evaluation of transport performance is thus vital to optimizing further molecule design. Yet, the routine method by means of the conventional field-effect transistors may not satisfy such a requirement. Here, it is shown that the extrinsic effects of Schottky barrier, access transport through semiconductor bulk, and concurrent ambipolar conduction seriously influence transport analysis. The planar transistors incorporating ohmic contacts free of access and ambipolar conduction afford an ideal access to charge transport. It is found, however, that only the planar transistors operating in low-field regime are reliable to explore the inherent transport properties due to the energetic disorder lowering by the lateral field induced by high drain voltage. This work opens up a robust approach to comprehend the delicate charge transport in conjugated polymers so as to develop high-performance semiconducting polymers for promising plastic electronics.
共轭聚合物迎来了一个前所未有的时代，即电荷输运仅受聚集区域内小的无序性限制。因此，准确评估输运性能对于进一步优化分子设计至关重要。然而，传统的场效应晶体管常规方法可能无法满足这一要求。在这里，我们表明肖特基势垒的外部效应、通过半导体体的接入传输以及同时的双极传导严重影响了传输分析。具有无接入和双极传导的欧姆接触的平面晶体管为电荷传输提供了理想的途径。然而，我们发现，由于高漏电压引起的横向场降低了能量无序，只有在低场模式下工作的平面晶体管才可靠地探索内在的输运性质。这项工作为理解共轭聚合物中微妙的电荷输运提供了一种稳健的方法，从而为有前途的塑料电子学开发高性能半导体聚合物。
