High-quality hexagonal boron nitride from 2D distillation
Hexagonal boron nitride (h-BN) is the key packaging material in two-dimensional (2D) materials field, though synthesis of high-quality h-BN has remained a major challenge. Cun at al. reported a new scheme to fabricate single layer h-BN

This single layer h-BN shows higher quality in view of mosaicity and strain variations than material from chemical vapour deposition (CVD)
Annealing back-transferred BN layer on catalytic substrates leads to 2D distillation, which produces superior quality h-BN. This provides low-cost way for 2D material production remote from CVD instrumentation.
The LEEM video shows the annealing transformation sequence from t-BN to m-BN and then to d-BN. The duration of the movie of 43 s covers 48 minutes real-time of the experiment. (The sample temperature changes from 853°C to 937°C . The field of view (FOV) is 23 µm.)
Publication:
ACS Nano https://pubs.acs.org/doi/10.1021/acsnano.0c08616
Authors: Huanyao Cun, Zichun Miao, Adrian Hemmi, Yasmine Al-Hamdani, Marcella Iannuzzi, Jürg Osterwalder, Michael S. Altman, and Thomas Greber