Doped N‐Type Organic Field‐Effect Transistors Based on Faux‐Hawk Fullerene
Doped N‐Type Organic Field‐Effect Transistors Based on Faux‐Hawk Fullerene
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DOI：
10.1002/aelm.201900109
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发表时间：
2019-05
影响因子：
6.2
通讯作者：
Shiyi Liu;Nicholas J. DeWeerd;B. Reeves;Long K. San;Drona Dahal;Raj Kishen Radha Krishnan;S. Strauss;O. Boltalina;B. Lüssem
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文献类型：
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作者：
Shiyi Liu;Nicholas J. DeWeerd;B. Reeves;Long K. San;Drona Dahal;Raj Kishen Radha Krishnan;S. Strauss;O. Boltalina;B. Lüssem
人造鹰富勒烯是高性能有机场效应晶体管（ofet）的有前途的候选材料。它们具有致密的分子堆积和高的热稳定性。此外，与大多数其他C60衍生物相比，氟化基团C6F4CF2对富勒烯核心的功能化不会增加它们的最低未占据轨道位置，这允许使用空气稳定的分子掺杂剂来优化它们的性能。研究了n掺杂对假鹰富勒烯1,9‐C60(cyclo‐CF2(2‐C6F4)) (C60FHF) ofet性能的影响。提出了一个n掺杂晶体管的解析模型，并用于阐明在掺杂ofet中通常观察到的亚阈值摆幅增加的来源。结果表明，在栅极介质/C60FHF层上采用块状掺杂层代替混合掺杂层可以减小亚阈值振荡的增加。经过优化后，ofet的平均电子迁移率为0.34 cm2 V−1 s−1，掺杂晶体管的亚阈值摆幅低于400 mV dec−1，接触电阻为10 kΩ cm，是基于富勒烯的n型半导体的最佳性能之一。
Faux‐hawk fullerenes are promising candidates for high‐performance organic field‐effect transistors (OFETs). They show dense molecular packing and high thermal stability. Furthermore, in contrast to most other C60 derivates, functionalization of the fullerene core by the fluorinated group C6F4CF2 does not increase their lowest unoccupied orbital position, which allows the use of air‐stable molecular n‐dopants to optimize their performance. The influence of n‐doping on the performance of OFETs based on the faux‐hawk fullerene 1,9‐C60(cyclo‐CF2(2‐C6F4)) (C60FHF) is studied. An analytic model for n‐doped transistors is presented and used to clarify the origin of the increase in the subthreshold swing usually observed in doped OFETs. It is shown that the increase in subthreshold swing can be minimized by using a bulk dopant layer at the gate dielectric/C60FHF layer instead of a mixed host:dopant layer. Following an optimization of the OFETs, an average electron mobility of 0.34 cm2 V−1 s−1, a subthreshold swing below 400 mV dec−1 for doped transistors, and a contact resistance of 10 kΩ cm is obtained, which is among the best performance for fullerene based n‐type semiconductors.