Controlled Adhesion of Ice—Toward Ultraclean 2D Materials (Adv. Mater. 14/2023)

Abstract

2D Materials It highlights the remarkable technological advances achieved in this work, that ice can be used to transfer 2D materials, yielding ultraclean and ultra‐uniform products. Compared to the traditional poly(methyl methacrylate) (PMMA) method for 2D materials transfer, which leads to contamination and rippling defects, the ice‐transfer method achieved by Jiong Zhao, Qingming Deng, Thuc Hue Ly, and co‐workers in article number 2210503 paves a new way for 2D materials science and technology.

Clean Transfer of Two-Dimensional Materials: A Comprehensive Review

“…More recently, the authors developed the ice-aided transfer and ice-stamp transfer methods, in which water (ice) is the only medium in the entire process (Figure ). The interaction between ice and 2D materials has always been an interesting topic due to the intriguing behaviors of ice on 2D surface or under confined space. − Being the most common natural material, ice exhibits strong adhesion to solid surfaces via a vdW interaction and hydrogen bonds. Interestingly, it is found that the adhesion of ice can be controlled by the environmental temperature, which makes it possible to detach 2D materials from the growth substrate by using ice.…”

“…By slowly rolling the lint roller at a temperature below 170 °C, the amorphous carbon on graphene surface is removed by the strong adhesion between activated carbon and the amorphous carbon (Figure d) . More recently, the authors have developed a post-transfer cleaning method called ice-cleaning (Figure e) . Since ice itself does not introduce additional contaminations and the adhesion of ice can be controlled by temperature, it is promising to clean the 2D materials using ice in a mechanical way.…”

“…Scale bar: 400 μm. Panels (e) and (f) were adapted with permission from ref . Copyright 2023 Wiley-VCH Verlag GmbH.…”

“…Overview of the cleanliness assessment techniques. Adapted with permission from ref . Copyright 2023 Wiley-VCH Verlag GmbH; adapted with permission from ref .…”

“…SEM and AFM are powerful tools to study the surface morphology of 2D materials on various scales. Especially, the AFM phase mode (noncontact mode) is sensitive to the surface contamination owing to the phase contrast attributed to the energy absorption of sample surface . In addition, TEM ,,, and scanning tunneling microscopy (STM) , are able to assess the sample quality in a nanoscale.…”