CO2脈衝雷射應用於PEDOT:PSS熱處理製程之研究

Abstract

本研究利用波長10600 nm的CO2脈衝雷射源，對PEDOT:PSS (CLEVIOS™ HIL-E 100 from Heraeuse)進行熱處理加工。本研究利用線性四點探針、分光光度法、原子力顯微鏡、掃描式電子顯微鏡、X光電子能譜對雷射熱處理前後的PEDOT:PSS性能進行探究。透過調變雷射參數，本研究成功建立PEDOT:PSS受CO2雷射熱處理之變化模式。過程中成功在181 s內把PEDOT:PSS電導率從2.83E-02 S/cm提升至5.94 E+01 S/cm。此電導率上升可能與SEM觀測到之PEDOT:PSS分子團聚現象以及XPS觀測到之表面PEDOT/PSS訊號強度比值從0.1359上升到0.2499有關。最高電導率加工參數加工相較於原試片，過程中伴隨可見光平均透光率從 89.1219 % 下降到 88.4766 % 以及方均根粗糙度從2.27 nm上升到2.49 nm等少量劣化。而材料表面累積能量過高時，會同時造成透光率以及電導率大幅下降。在加熱板對照組實驗中，同樣在空氣中進行熱處理，加熱板並無法在30 min內將此材料電導率有效提升，證明本研究提出之PEDOT:PSS熱處理方法在小面積並且無加工環境氣體控制設備下有其優勢。 本研究發現CO2脈衝雷射運用於PEDOT:PSS熱處理是十分具有競爭力，可以在相對短的時間內對小面積PEDOT:PSS進行有效熱處理。搭配上選擇性加工的優勢可以將可撓性透明電子元件複雜度以及材料的選用增加更多可能。

In this study, the PEDOT:PSS (CLEVIOS™ HIL-E 100 from Heraeuse) films coated on glass substrate was treated by CO2 pulsed laser in the air. The property of the PEDOT:PSS was investigated by in-line four-point probe array, spectrophotometry, AFM, SEM, and XPS. Through manipulating the fluence and the scan speed of the laser, the change in PEDOT:PSS property induced by CO2 pulsed laser was analyzed. The conductivity of the film was enhanced from 2.83E-02 S/cm to 59.4 S/cm in 181 seconds as a result of the remove of the residual water. Meanwhile, the average transmittance decreased from 89.1219 % to 88.4766 %, and the RMS roughness increased from 2.27 nm to 2.49 nm. The conductivity enhancement might be caused by the reunion between PEDOT:PSS moleculars, and the rise in the surface PEDOT/PSS ratio as investigated by SEM and XPS. However, when the laser power excess the durability of PEDOT:PSS, some significant decrease in conductivity and transmittance was observed. Compared with the hotplate thermal traetment in the air, which can not significantly increase the conductivity of PEDOT:PSS, it is found that CO2 pulsed laser thermal treatment have advantages in PEDOT:PSS thermal treatment in small area without air controled. In this study, a promising method of heat treatment for PEDOT:PSS is investigated. The conductivity of PEDOT:PSS is enhanced to 59.4 S/cm in air by CO2 Laser, which is much better than hotplate. With the advantage of selective treatment, the heat can be controled for more complicated electrical stucture in the future.