July 18, 2022, 3:45 p.m.

In‐Situ TEM observation of Oswald ripening in germanium growth on freestanding graphene and its application to wafer scale layer transfer process (PEELER)

In‐situ High resolution transmission electron microscopy (HR‐TEM) dynamic investigation of the nucleation of germanium islands on free standing graphene allow direct observation of basic phenomenon such as island nucleation, growth and coalescence. The experimental observations demonstrate that nucleation is enhanced by low temperature deposition, and that the coarsening process is dominated by Oswald ripening, this latter phenomenon leads to monocrystalline coalescence when it occurs below a certain critical size.

These basic observations have been applied to mesoporous germanium in order to design and fabricate detachable monocrystalline nanomembranes. We have demonstrated the first wafer scale detachable and flexible germanium nanomembrane through the new so‐called PEELER process, the substrate can be re‐used to produce more nanomembranes in the same fashion as the remote epitaxy process enabling layer separation and transfer for non‐polar group IV‐IV materials. It is shown that this substrate is compatible with MOCVD growth of device quality materials.

Abderraouf Boucherif has been an assistant professor of mechanical engineering at Université de Sherbrooke since 2018. He is the 2020 winner of the Tremplin Prize in Natural science and Engineering. His research is focused on semiconductor nanomaterials for green energy. Leading a multidisciplinary team of more than 20 scientists and students, he is the principal investigator of large-scale research projects in partnership with industry to create new nanomaterial for solar energy applications. Among his major achievements is the demonstration of a process for semiconductor layer transfer and substrate recycling as well as defect free III-V virtual substrate on silicon. He has published more than 70 papers in international peer reviewed journals and received several awards for his outstanding applied research contributions. Here is a link to his detailed CV.