Innovations in Atomic and Molecular Layer Deposition of Rare Earth-Based Functional Thin Films: Expanding Horizons in Electronics and Optoelectronics

In a recent article, researches from Germany (Bochum University) and Finland (Aalto University) explore the evolution and advancements in the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques for rare earth-based thin films, emphasizing their role in diverse applications ranging from microelectronics to optoelectronics and medical diagnostics. Initially focused on developing rare earth oxides as high-k dielectric materials in semiconductor devices, research has expanded to include complex ternary and quaternary perovskite oxides with unique magnetic and catalytic properties. The recent surge in ALD/MLD techniques has enabled the creation of rare earth-organic hybrid materials with intriguing luminescence properties, promising new avenues for applications in lighting, imaging, and solar cells.

Survey over the different rare earth precursor classes commonly employed for the ALD and ALD/MLD of rare earth containing thin films. Color bars indicate successful ALD employment of the compound class for the respective element. R represents an element of the extended rare earth elements, while R’ and R’’ refer to specific substituents. These are: H = Hydrogen, Me = Methyl, Et = Ethyl, iPr = Isopropyl, nBu = Butyl, tBu = Tert-butyl.

The review also highlights the challenges associated with precursor development and the need for further research to optimize the chemical reactivity and long-term stability of these materials. The potential for these novel materials to revolutionize industries is significant, particularly in the creation of flexible devices and advanced optoelectronic applications. However, according to the article, achieving widespread industrial adoption will require continued collaboration between academia and industry to refine processes, enhance material performance, and ensure scalability.

Annually published ALD and ALD/MLD articles involving rare earth elements from 1992 to 2023. The publications were searched from Scopus and Web of Science, using search terms that included “atomic layer deposition” and “rare earth”, or “atomic layer deposition” and “lanthanide”. The data thus acquired were further manually refined to check for numbers as accurate as possible. Data were accessed lastly on 10-02-2024.

Source: Atomic and Molecular Layer Deposition of Functional Thin Films Based on Rare Earth Elements - Ghazy - Advanced Materials Interfaces - Wiley Online Library