Catalyst-free growth of two-dimensional hexagonal boron nitride few-layers on sapphire for deep ultraviolet photodetectors

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2019, Vol.7 (47), p.14999-156
• Main Authors: Gao, Menglei, Meng, Junhua, Chen, Yanan, Ye, Siyuan, Wang, Ye, Ding, Congyu, Li, Yubo, Yin, Zhigang, Zeng, Xiangbo, You, Jingbi, Jin, Peng, Zhang, Xingwang
• Format: Article
• Language: English
• Subjects: Boron nitride; Catalysts; Chemical synthesis; Crystal defects; Electronic devices; Ion beam sputtering; Lattice vacancies; Photometers; Photonics; Sapphire; Substrates; Transition metals; Ultraviolet detectors
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c9tc05206b

Two-dimensional (2D) hexagonal boron nitride (h-BN) is a promising candidate as a supporting substrate, a gate dielectric and a protecting layer for 2D electronic and photonic devices. Transition metals were usually adopted as substrates for the synthesis of 2D h-BN, however, catalyst-free growth of high-quality h-BN on dielectric substrates is still very challenging. Herein, we report the catalyst-free growth of 2D h-BN few-layers on sapphire substrates by ion beam sputtering deposition (IBSD). We find that the h-BN grown under conventional conditions is nonstoichiometric with an excess of B element, resulting in a large number of N vacancy defects and poor crystalline quality. The wafer-scale high quality 2D h-BN layers were synthesized on sapphire by the combination of surface nitridation and N + sputtering. Furthermore, the 2D h-BN few-layers on sapphire were used to fabricate deep ultraviolet photodetectors, which exhibit better performance in comparison with the devices fabricated by the transferred h-BN. Catalyst-free growth of wafer-scale h-BN few-layers is realized on sapphire substrates by the combination of surface nitridation and N + sputtering.