Towards n-type conductivity in hexagonal boron nitride

• Published in: Nature communications 2022-06, Vol.13 (1), p.3109-3109, Article 3109
• Main Authors: Lu, Shiqiang, Shen, Peng, Zhang, Hongye, Liu, Guozhen, Guo, Bin, Cai, Yehang, Chen, Han, Xu, Feiya, Zheng, Tongchang, Xu, Fuchun, Chen, Xiaohong, Cai, Duanjun, Kang, Junyong
• Format: Article
• Language: English
• Subjects: 119/118; 147/135; 147/136; 147/137; 147/143; 147/28; 147/3; 639/301/1019/1020/1089; 639/301/357/1018; Asymmetry; Boron; Boron nitride; Chemical vapor deposition; Conduction; Conductivity; Coupling (molecular); Electronics industry; Gallium nitrides; Heterojunctions; Hole conductivity; Humanities and Social Sciences; Impurities; Ionization; Low pressure; Monolayers; multidisciplinary; Optoelectronic devices; Science; Science (multidisciplinary); Semiconductors; Transport properties; Trimers; Wide bandgap semiconductors
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-30762-1

Asymmetric transport characteristic in n - and p -type conductivity has long been a fundamental difficulty in wide bandgap semiconductors. Hexagonal boron nitride (h-BN) can achieve p -type conduction, however, the n -type conductivity still remains unavailable. Here, we demonstrate a concept of orbital split induced level engineering through sacrificial impurity coupling and the realization of efficient n -type transport in 2D h-BN monolayer. We find that the O 2 p z orbital has both symmetry and energy matching to the Ge 4 p z orbital, which promises a strong coupling. The introduction of side-by-side O to Ge donor can effectively push up the donor level by the formation of another sacrificial deep level. We discover that a Ge-O 2 trimer brings the extremely shallow donor level and very low ionization energy. By low-pressure chemical vapor deposition method, we obtain the in-situ Ge-O doping in h-BN monolayer and successfully achieve both through-plane (~100 nA) and in-plane (~20 nA) n -type conduction. We fabricate a vertically-stacked n -hBN/ p -GaN heterojunction and show distinct rectification characteristics. The sacrificial impurity coupling method provides a highly viable route to overcome the n -type limitation of h-BN and paves the way for the future 2D optoelectronic devices. Asymmetric n/p conductivity is a fundamental difficulty in wide bandgap semiconductors. Here the authors demonstrate a concept of orbital level engineering through sacrificial impurity coupling to achieve n-type conductivity (ne ~1016 cm -3 ) in hexagonal BN.