Insights into growing flexible single crystals could help develop new electronics materials

Creating flexible single crystal heterostructures could enable the next generation of flexible electronics and bioelectronics. A synthesis technique called remote epitaxy has been used to create such materials by growing a single crystal thin film across a layer of graphene. Notably, remote epitaxy can be used to grow complex oxides — which have many promising characteristics for applications in electronics — but researchers haven’t figured out how this growth occurs.

Yan et al. used in situ synchrotron X-ray measurements to study this growth in detail for the first time. The measurements allowed the team to watch the growth of individual oxide monolayers and understand their structure across the graphene. They also determined the effect of oxygen partial pressure, a property that is known to affect film properties and graphene structural integrity.

The results showed that for some phase and oxygen concentrations, the films are much easier to grow. However, they suggest it’s possible to create multilayered oxides with controllable stoichiometries, which could lead to creating a wide array of flexible structures.

“We are at the tip of the iceberg with regards to this technology,” said author Dillon Fong. “By understanding how these films grow on graphene, we can not only optimize their properties but also synthesize new heterostructures, joining together materials and creating interfaces that previously could not exist due to intrinsic incompatibilities.”

The researchers plan to investigate other aspects of remote epitaxy with in situ X-ray measurements, including growing materials with exotic phase transitions on graphene.

Source: “In situ X-ray studies of growth of complex oxides on graphene by molecular beam epitaxy,” by Xi Yan, Hui Cao, Yan Li, Hawoong Hong, David J. Gosztola, Nathan P. Guisinger, Hua Zhou, and Dillon D. Fong, APL Materials (2022). The article can be accessed at https://doi.org/10.1063/5.0101416 .

This paper is part of the Materials Challenges and Synthesis Science of Emerging Quantum Materials Collection, learn more here .