Organic thin-film transistors with flame-annealed contacts
Organic thin-film transistors with flame-annealed contacts
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DOI：
10.1088/2058-8585/ab76e1
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发表时间：
2020-03
影响因子：
3.1
通讯作者：
Matthew Waldrip;Hamna F. Iqbal;Andrew Wadsworth;I. McCulloch;O. Jurchescu
中科院分区：
文献类型：
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作者：
Matthew Waldrip;Hamna F. Iqbal;Andrew Wadsworth;I. McCulloch;O. Jurchescu
降低接触电阻是开发高性能有机场效应晶体管(OFET)的关键，因为它影响器件的迁移率和开关速度。通过对触点应用化学处理，如自组装单分子膜(SAM)、氧化物夹层或掺杂剂，电荷注入和收集得到了优化。在这里，我们测试了电极表面的火焰退火对接触电阻的界面和整体分量以及整体器件性能的影响。使用丁烷微炬对金电极进行闪光退火，使金颗粒结晶成更大的微区。我们发现，随着晶粒度的增大，触头的表面粗糙度也随之增加。由于表面粗糙度较大，SAM处理在火焰退火电极上产生的功函数漂移比沉积在未经处理的表面上的功函数移动更小。这导致了较大的界面接触电阻。然而，火焰退火也使半导体层中的陷阱态密度降低了一个数量级，从而降低了体接触电阻和沟道电阻。这些相互竞争的效应使OFET的性能与未经处理的器件相似。
Reducing contact resistance is critical to developing high-performance organic field-effect transistors (OFETs) since it impacts both the device mobility and switching speed. Charge injection and collection has been optimized by applying chemical treatments to the contacts, such as self-assembled monolayers (SAMs), oxide interlayers, or dopants. Here, we tested how flame annealing the surface of the electrodes impacts the interface and bulk components of the contact resistance, as well as the overall device performance. A butane micro torch was used to flash-anneal the gold electrodes, which allowed gold grains to crystallize into larger domains. We found that, along with the grain size, the surface roughness of the contacts was also increased. SAM treatment created a lower work function shift on a flame annealed electrode than when deposited on an untreated surface, due to the greater surface roughness. This resulted in a larger interface contact resistance. However, flame annealing also produced an order of magnitude reduction in the density of trap states in the semiconductor layer, which reduced the bulk contact resistance and channel resistance. These competing effects yielded OFETs with similar performance as untreated devices.