Molecular Layer-Defined Transition of Carrier Distribution and Correlation with Transport in Organic Crystalline Semiconductors
Molecular Layer-Defined Transition of Carrier Distribution and Correlation with Transport in Organic Crystalline Semiconductors
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有机晶体半导体中载流子分布的分子层定义转变及其与传输的相关性
DOI：
10.1021/acsami.0c04873
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发表时间：
2020
影响因子：
9.5
通讯作者：
Li Yun
中科院分区：
文献类型：
--
作者：
Jiang Sai;Wang Qijing;Qian Jun;Guo Jianhang;Duan Yiwei;Wang Hengyuan;Shi Yi;Li Yun
尽管人们在揭示有机场效应晶体管半导体/介电界面的载流子行为方面付出了巨大的努力，但对分子晶体半导体中载流子分布及其与电荷输运的关系的研究仍然是理解微观载流子运动本质的基础。因此，寻找一种具有分子层精度的精确调节载流子分布的有效方法至关重要。在这里，我们发现通过调节载流子和介电介质之间的极化耦合，载流子积累在高度有序的、少层的分子晶体半导体薄膜中被严格调节。导纳方法表明，载流子仅分布在高-κ介电条件下具有较强局域性的单层内，而在低-κ介电条件下则扩展到具有较好局域性的第二层。此外，通过温度相关的测量，在晶体管结构下证明了介电界面电荷输运的独特尺寸跃迁。分子晶体薄膜中具有层定义精度的载流子的微观性质将在界面工程、量子输运和器件物理方面为有机电子学提供前所未有的机会。
Despite the great efforts to unveil the charge carrier behavior at the semiconductor/dielectric interface of organic field-effect transistors, an examination of the interfacial carrier distribution and the correlation with the charge transport in molecular crystalline semiconductors remains fundamental for understanding the nature of the microscopic carrier motion. Hence, an effective approach to accurately tune the carrier distribution with molecular-layer precision is essential. Here, we find that the carrier accumulation is strictly modulated in highly ordered, few-layer molecular crystalline semiconducting films by tuning the polaronic coupling between the charge carriers and dielectric. The admittance method reveals that the carriers distribute only within a monolayer with stronger localization on a high-κ dielectric and extend to a second layer with better delocalization on a low-κ dielectric. Furthermore, a unique dimensional transition in the charge transport at the dielectric interface is evidenced under a transistor architecture by temperature-dependent measurements. The presented microscopic nature of charge carriers with layer-defined precision in molecular crystalline films should provide an unprecedented opportunity in organic electronics in terms of interface engineering, quantum transport, and device physics.