Park Yoonsu, Jeong Wooseok, Ahn Junhyuk, Hong Yun-Kun, Hwang Eunseo, Kim Minyoung, Hwang Yun Jae, Oh Soong Ju, Ha Don-Hyung
School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul06974, Republic of Korea.
Department of Materials Science and Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea.
ACS Omega. 2022 Nov 1;7(45):41021-41032. doi: 10.1021/acsomega.2c04366. eCollection 2022 Nov 15.
A strong interparticle connection needs to be realized to harvest unique nanoscale features of colloidal nanoparticles (NPs) in film structures. Constructing a strong contact and adhesion of NPs on a substrate is an essential process for improved NP film properties, and therefore, its key factors should be determined by understanding the NP deposition mechanism. Herein, we investigated the critical factors leading to the robust and strong adherence of the film structure and revealed that the NP deposition mechanism involved the role of surfactant ligands during electrophoretic deposition (EPD). The high amount of surfactant ligand treatment results in a high deposition rate of NPs in the early stage; however, the ligand treatment does not influence the deposition rate in the later stage. Furthermore, the deposition mechanism is found to involve three steps during EPD: island formation, lateral growth, and layer-by-layer deposition. Rapid NP deposition kinetics controlled by ligand treatments demonstrate the strong contact and adhesion of NP film structures; they are characterized by the fast charge transfer, low resistivity, and rigid NP layers of the Cu S NP-based devices. Finally, the controlled role of surfactant ligands in EPD enables design of high-performance nanostructured NP film devices with contact enhancement.
为了在薄膜结构中利用胶体纳米颗粒（NPs）独特的纳米级特性，需要实现颗粒间的强连接。在基底上构建NPs的强接触和粘附是改善NP薄膜性能的关键过程，因此，其关键因素应通过了解NP沉积机制来确定。在此，我们研究了导致薄膜结构牢固且强粘附的关键因素，并揭示了NP沉积机制涉及表面活性剂配体在电泳沉积（EPD）过程中的作用。大量表面活性剂配体处理导致早期NP的沉积速率较高；然而，配体处理在后期并不影响沉积速率。此外，发现沉积机制在EPD过程中涉及三个步骤：岛状形成、横向生长和逐层沉积。由配体处理控制的快速NP沉积动力学证明了NP薄膜结构的强接触和粘附；它们的特征在于基于CuS NP的器件具有快速电荷转移、低电阻率和刚性NP层。最后，表面活性剂配体在EPD中的可控作用使得能够设计出具有接触增强功能的高性能纳米结构NP薄膜器件。
