Damage-free Metal Electrode Transfer to Monolayer Organic Single Crystalline Thin Films
Damage-free Metal Electrode Transfer to Monolayer Organic Single Crystalline Thin Films
复制标题
DOI：
10.1038/s41598-020-61536-8
复制
发表时间：
2020-03-13
影响因子：
4.6
通讯作者：
Takeya, Jun
中科院分区：
文献类型：
--
作者：
Makita, Tatsuyuki;Yamamura, Akifumi;Takeya, Jun
溶液处理有机薄膜晶体管（OTFT）是下一代印刷电子器件的重要组成部分。有机半导体（OSC）能够自发形成分子组装体，在有机薄膜晶体管（OTFT）的制备中起着至关重要的作用。OTFT制造工艺由功能层的顺序沉积组成，这固有地在实现理想特性方面带来显著困难，因为底层可能被后续层的施加损坏。当直接在OSC表面上形成金属接触电极时，由于真空蒸发期间的热损伤和随后的光刻期间溶剂的影响，这些困难特别突出。在这项工作中，我们展示了一种简单易行的技术，将接触电极转移到超薄OSC薄膜并形成理想的金属/OSC界面。使用聚合物双层薄膜转移和层压光刻限定的金属电极。一层是厚的牺牲聚合物膜，其使得整个膜更容易处理并且是水溶性的以便稍后溶解。另一种是薄缓冲膜，帮助模板静电粘附到基底上。本技术不会在衬底OSC层中引起任何致命的损伤，这导致成功地制造由单层OSC膜组成的OTFT，其迁移率高于10 cm（2）V-1 s（-1），亚阈值摆幅小于100 mV decade（-1），并且接触电阻低至175 Ω. cm。通过单层OTFT的10 × 10阵列的操作证实了有效接触制造的再现性。这里开发的技术不仅为实际的OTFT制造，而且还可能为所有现有的垂直堆叠有机器件，如发光二极管和太阳能电池，迈出了关键的一步。
Solution-processed organic thin film transistors (OTFTs) are an essential building block for nextgeneration printed electronic devices. Organic semiconductors (OSCs) that can spontaneously form a molecular assembly play a vital role in the fabrication of OTFT s. OTFT fabrication processes consist of sequential deposition of functional layers, which inherently brings significant difficulties in realizing ideal properties because underlayers are likely to be damaged by application of subsequent layers. These difficulties are particularly prominent when forming metal contact electrodes directly on an OSC surface, due to thermal damage during vacuum evaporation and the effect of solvents during subsequent photolithography. In this work, we demonstrate a simple and facile technique to transfer contact electrodes to ultrathin OSC films and form an ideal metal/OSC interface. Photolithographically defined metal electrodes are transferred and laminated using a polymeric bilayer thin film. One layer is a thick sacrificial polymer film that makes the overall film easier to handle and is water-soluble for dissolution later. The other is a thin buffer film that helps the template adhere to a substrate electrostatically. The present technique does not induce any fatal damage in the substrate OSC layers, which leads to successful fabrication of OTFTs composed of monolayer OSC films with a mobility of higher than 10 cm(2) V-1 s(-1), a subthreshold swing of less than 100 mV decade(-1), and a low contact resistance of 175 Omega.cm. The reproducibility of efficient contact fabrication was confirmed by the operation of a 10 x 10 array of monolayer OTFTs. The technique developed here constitutes a key step forward not only for practical OTFT fabrication but also potentially for all existing vertically stacked organic devices, such as light-emitting diodes and solar cells.