有機無機混成材料於光電元件之創新印刷製程

Innovative printing process of organic-inorganic hybrid materials for optoelectronic applications

彭宣穎(Shiuan-Ying Peng)

指導教授 ： 廖英志

國立臺灣大學/工學院/化學工程學研究所/博士(2021年)

https://doi.org/10.6342/NTU202101764

摘要

隨著現今塗佈技術的廣泛應用，塗佈之薄膜可以應用在電致變色裝置、太陽能電池等。塗佈過程系指將調配之墨水，塗在基材上並經過乾燥後成膜的過程。塗佈技術的種類繁多，其中接觸式塗佈如:旋轉塗佈和點膠塗佈。非接觸式塗佈如:噴霧塗佈和噴墨塗佈等。上述各種塗佈方式都可以歸納為三大程序：墨水調配、塗佈方法、和薄膜熱燒結後處理。裝置的性能與薄膜塗佈品質有高度相關，每一個步驟都會影響到塗佈出的薄膜品質。本研究論文將整合上述程序，發展出創新的製程，並應用於光電裝置進而提升裝置性能。
在實際塗佈薄膜的應用上，常會在墨水中加入相對應的功能性奈米材料。在第二章中，為了製備耐刮的電解質薄膜，我們添加奈米纖維素於電解質墨水中，成膜後的電解質薄膜同時兼具高穿透、高導電度和高耐刮強度等特性，適合應用在電致變色複寫紙。具手寫功能的電致變色複寫裝置也被進一步的研究著色效率、反應時間和可撓度等。這個可複寫的電致變色裝置扮演了資訊儲存的重要腳色。
墨水塗佈在基材乾燥形成薄膜時，容易產生咖啡環狀沉積。在不改變墨水和基板的情況下，為了使薄膜均勻，需要一創新的噴塗方法。在第三章中，我們發展出一種利用雙噴頭噴塗結合反溶劑結晶的方法。通過此方法可以避免在高表能基材容易出現咖啡環狀結晶的問題。控制反溶劑與前驅液結合的位置，能準確成長鈣鈦礦晶核在指定的位置。印製出的單晶鈣鈦礦的粒徑尺寸從奈米到毫米都可以調整。此外，透過調整結合的位置，晶體成長方向不只x-y平面也可以沿著z軸成長。這種創新的噴墨單晶的方法也能應用至其他結晶程序。
為了提升薄膜性能，塗佈的薄膜通常要經過進一步的後處理，然而傳統的熱燒結溫度過高容易破壞有機材料和損毀基板，在應用上有限制。在第四章中，我們發展出一新穎的脈衝光燒結，快速製備連續能隙鈣鈦礦吸光層應用至太陽能電池為例。MAPbI3膜和MAPbBr3膜之間的界面經由脈衝光(IPL)燒結後，在1 ms內可以生成碘溴混合的鈣鈦礦(MAPbBr3-xIx)膜。IPL燒結出的連續能隙鈣鈦礦有很高的穩定性，即便在高強度的光照射下都不會相分離。將連續能隙組裝成太陽能電池能明顯改善光電轉換效率。這種由脈衝光快速燒結界面的程序可以進一步應用在其他材料上。
最後總結經由印刷塗佈製備光電裝置並改善整個印刷塗佈過程中的塗佈品質以提升裝置性能，這些光電製成製程上的改善和創新為了也可以應用至其他領域或是為商業化放大製程作先期的評估改善。

關鍵字

功能性墨水 ； 液滴結合 ； 脈衝光燒結 ； 電致變色 ； 噴墨長單晶 ； 太陽能電池

並列摘要

With the widespread application of coating technology, the coated thin films can be used in electrochromic devices and solar cell applications. The coating process refers to the process of coating inks on the substrate to form films. There are many types of coating technology, including contact coating such as spin coating and dispensing coating. Non-contact coating such as spray coating and inkjet coating. The above-mentioned coating methods can be summarized into three major procedures: adjustment of ink formulation, coating method, and film post-treatment via thermal sintering. The performance of the device is highly correlated with the film quality. This thesis integrates the above procedures to develop innovative processes to improve film quality for optoelectronic applications.
In the actual application of coating films, the corresponding functional nanomaterials are often added to the ink. In Chapter 2, we add nanocellulose into electrolyte inks to fabricate anti-scratch films. The coated electrolyte films have the characteristics of high transparency, high conductivity and high scratch resistance, that is suitable to apply in electrochromic rewritable paper. The electrochromic devices with handwriting function were further investigated the color efficiency, response time, and flexibility. This rewritable electrochromic rewritable paper which plays a role of the information storage device.
When the inks are coated on the substrate and dried as thin film, it is easily to produce coffee ring deposits. To deposit the film on the designed position without changing the ink and substrate, novel printing methods are needed. In Chapter 3, we developed a coalescing anti-solvent crystallization method by using a dual nozzle printer. This method can avoid the undesired coffee ring shaped crystals deposition on the high surface energy substrate. Controlling the position where the anti-solvent coalesces with the precursor liquid can accurately grow the perovskite nucleus at the specified position. The printed single crystal perovskite shows tunable grain size from nanometer to millimeter. Moreover, the crystals can grow along not only x-y plane but also z-axis direction by adjusting coalescing position. This innovative inkjet printing single crystal method can also be applied to other crystallization procedures.
To improve the performance of the coated film which usually undergoes further post-treatment. However, the traditional thermal annealing has limitations in application. The annealing temperature is usually too high that easily damage the organic materials or damage the substrates. In Chapter 4, we developed an intense pulsed light (IPL) sintering process to fabricate gradient band gap perovskite films (MAPbBr3/ MAPbBr3-xIx/ MAPbI3) as a light-absorbing layer are prepared for solar cells. The interface between MAPbI3 film and MAPbBr3 QD film was produced the mixed perovskite (MAPbBr3-xIx) film within 1 ms after intense pulsed light (IPL) sintering. The gradient perovskite by IPL sintering shows high stability without phase separation. The assembled solar cell with gradient perovskite film significantly improves the power conversion efficiency. This rapid interface sintering process by IPL can further extend to other materials.
Finally, in Chapter 5, we summarize and integrate the contributions of this paper. The coating process is improved to enhance the performance of the optoelectronic devices. These improvements and innovations in the optoelectronics manufacturing process can also be further applied to other fields.

並列關鍵字

Functional ink ； Droplet coalescence ； Intense pulse sintering ； Electrochromic ； Inkjet-printed single crystal ； Solar cell

參考文獻

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