High-Speed Photothermal Patterning of Doped Polymer Films
High-Speed Photothermal Patterning of Doped Polymer Films
复制标题
掺杂聚合物薄膜的高速光热图案化
DOI：
10.1021/acsami.9b15860
复制
发表时间：
2019
影响因子：
9.5
通讯作者：
Grigoropoulos, Costas P.
中科院分区：
文献类型：
--
作者：
Su, Zhengliang;Bedolla-Valdez, Zaira I.;Wang, Letian;Rho, Yoonsoo;Chen, Sunny;Gonel, Goktug;Taurone, Eric N.;Moulé, Adam J.;Grigoropoulos, Costas P.
有机半导体（OSC）为下一代电子产品提供了一条新途径，但缺乏可扩展且廉价的纳米级图案化/沉积技术仍然限制了它们在电子应用中的使用。最近，推出了一种新的光刻蚀刻技术，该技术使用分子掺杂剂来降低半导体聚合物在溶剂中的溶解度，并使用直写激光来局部去除掺杂剂，从而实现具有衍射有限分辨率的快速 OSC 蚀刻。先前的出版物假设，实现图案化的反应是光激发掺杂剂与中性溶剂分子之间的光化学反应。在这项工作中，我们使用时间分辨原位光学探测分析了 F4TCNQ 掺杂 P3HT 薄膜的光致溶解动力学。我们发现了控制去掺杂和溶解的两种竞争机制：第一个是文献中提出的光化学反应，第二个涉及激光直接加热聚合物，从而增加聚合物和掺杂剂的溶解度。我们表明，在低光子剂量下，特定波长的光化学效应占主导地位，而无论激光波长如何，在高激发速率下，光热效应占主导地位。在足够高的光强度输入下，光热机制原则上可以实现高达1 m/s的高写入速度。我们的研究结果为基于掺杂诱导溶解度控制的激光直写 OSC 背后的机制带来了新的见解，并能够在大规模制造中超精密制造各种器件配置。
Organic semiconductors (OSCs) offer a new avenue to the next-generation electronics, but the lack of a scalable and inexpensive nanoscale patterning/deposition technique still limits their use in electronic applications. Recently, a new lithographic etching technique has been introduced that uses molecular dopants to reduce semiconducting polymer solubility in solvents and a direct-write laser to remove dopants locally, enabling rapid OSC etching with diffraction limited resolution. Previous publications postulated that the reaction that enables patterning is a photochemical reaction between photoexcited dopants with neutral solvent molecules. In this work, we analyze the photoinduced dissolution kinetics of F4TCNQ doped P3HT films using time-resolved in situ optical probing. We find two competing mechanisms that control de-doping and dissolution: the first is the photochemical reaction posited in the literature, and the second involves direct heating of the polymer by the laser, inducing increased solubility for both the polymer and dopant. We show that the wavelength-specific photochemical effect is dominant in low photon doses while the photothermal effect is dominant with high excitation rates regardless of laser wavelength. With sufficiently high optical intensity input, the photothermal mechanism can in principle achieve a high writing speed up to 1 m/s. Our findings bring new insights into the mechanisms behind laser direct writing of OSCs based on dopant induced solubility control and enable ultraprecise fabrications of various device configurations in large-scale manufacturing.