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Wafer-scale AA-stacked hexagonal boron nitride grown on a GaN substrate 
Auteur(s): Moon Seokho, Okello Odongo Francis Ngome, Rousseau A., Choi Chang-Won, Kim Youngjae, Park Yunjae, Kim Jiye, Kim Jaewon, Kim Minhyuk, Valvin P., Cho Jaehee, Watanabe Kenji, Taniguchi Takashi, Jeong Hu Young, Fugallo Giorgia, Desrat W., Ding Feng, Lee Jaedong, Gil B., Cassabois G., Choi Si-Young, Kim Jong Kyu
(Article) Publié:
Nature Materials, vol. p. (2025)
Ref HAL: hal-05037685_v1
DOI: 10.1038/s41563-025-02173-2
Exporter : BibTex | endNote
Résumé: The stacking sequence of two-dimensional hexagonal boron nitride (hBN) is a critical factor that determines its polytypes and its distinct physical properties. Although most hBN layers adopt the thermodynamically stable AA′ stacking sequence, achieving alternative stacking configurations has remained a long-standing challenge. Here we demonstrate the scalable synthesis of hBN featuring unprecedented AA stacking, where atomic monolayers align along the c axis without any translation or rotation. This previously considered thermodynamically unfavourable hBN polytype is achieved through epitaxial growth on a two-inch single-crystalline gallium nitride wafer, using a metal–organic chemical vapour deposition technique. Comprehensive structural and optical characterizations, complemented by theoretical modelling, evidence the formation of AA-stacked multilayer hBN and reveal that hBN nucleation on the vicinal gallium nitride surface drives the unidirectional alignment of layers. Here electron doping plays a central role in stabilizing the AA stacking configuration. Our findings provide further insights into the scalable synthesis of engineered hBN polytypes, characterized by unique properties such as large optical nonlinearity.
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