Ultrasmooth Epitaxial Pt Thin Films Grown by Pulsed Laser Deposition

• Published in: ACS applied materials & interfaces 2024-01, Vol.16 (1), p.1921-1929
• Main Authors: Torres-Castanedo, Carlos G., Buchholz, D. Bruce, Pham, Thang, Zheng, Liyang, Cheng, Matthew, Dravid, Vinayak P., Hersam, Mark C., Bedzyk, Michael J.
• Format: Article
• Language: English
• Subjects: 4D-STEM; epitaxy; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; lithium manganese oxide; lithium-ion battery; platinum; pulsed laser deposition; Surfaces, Interfaces, and Applications
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c16065

Platinum (Pt) thin films are useful in applications requiring high-conductivity electrodes with excellent thermal and chemical stability. Ultrasmooth and epitaxial Pt thin films with single-crystalline domains have the added benefit of providing ideal templates for the subsequent growth of heteroepitaxial structures. Here, we grow epitaxial Pt (111) electrodes (ca. 30 nm thick) on sapphire (α-Al2O3 (0001)) substrates with pulsed laser deposition. This versatile technique allows control of the growth process and fabrication of films with carefully tailored parameters. X-ray scattering, atomic-force microscopy, and electron microscopy provide structural characterization of the films. Various gaseous atmospheres and temperatures were explored to achieve epitaxial growth of films with low roughness. A two-step (500 °C/300 °C) growth process was developed, yielding films with improved epitaxy without compromising roughness. The resulting films possess ultrasmooth interfaces (