• • PECVD using elemental B and N2 achieves wafer-scale hBN growth on Cu substrates, with monolayer flakes ~1 nm thick and uniform over the entire flake, enabling scalable production for industrial integration.
• • Isotopic enrichment (10B, 11B, 14N2, 15N2) yields tunable phonon mode shifts that quantitatively match harmonic oscillator predictions, providing precise control over thermal and optical properties.
• • Dynamic B source switching enables fabrication of in-plane h10BN-h11BN heterostructures, a previously unexplored architecture for quantum and phononic engineering.
• • The growth follows Frank-van der Merwe (layer-by-layer) mode, with first-layer growth taking longer (e.g., 30 min vs. 10 min for subsequent layers in similar PECVD), indicating van der Waals epitaxy on pre-existing hBN surfaces.