It has become a reality to use nitrogen and boron-containing alloys to control the preparation of large-area hexagonal boron nitride (h-BN), but there are few systematic studies on this growth mechanism, which hinders the large-size and high-quality h-BN. Control synthesis and practical application.
Recently, the research team of Wu Tianru, an associate researcher of the Shanghai Institute of Microelectronics and Information Technology of the Chinese Academy of Sciences and the research team of Professor Yuan Qinghong of East China Normal University, based on in-situ synthesis, characterization research and first-principles calculation methods, proposed the high surface of iron-boron (Fe2B) alloy. A new mechanism for mass multi-layer hexagonal boron nitride (h-BN) atom vacancy assisted growth.
Wu Tianru’s research team realized high-quality h-BN controllable preparation based on the Fe2B alloy system, and analyzed the B and N atoms in the Fe2B superficial layer during the synthesis of h-BN through rapid cooling quenching technology combined with time-of-flight secondary ion mass spectrometry (ToF-SIMS) Distribution.
Yuan Qinghong’s research team used first-principles calculation methods to study the growth mechanism of h-BN on Fe2B surface and proposed a vacancy-assisted synthesis mechanism for h-BN on Fe2B surface. Studies have found that the formation of B-N dimers causes a large number of B vacancies to be formed on the alloy surface, which greatly promotes the migration of B and N atoms.
In this work, on the basis of density functional theory (DFT) calculations and experiments, the vacancy-assisted growth mechanism of h-BN on Fe2B substrates was revealed. The study found that the h-BN nucleation energy barrier on Fe2B surface is about 2eV. Therefore, it is possible to synthesize h-BN at a relatively low temperature (700K).
The new "vacancy-assisted" growth mechanism proposed by this research solves the problem of the traditional method of synthesizing multilayer h-BN for a long time lacking catalysts with high N solubility and diffusion rate, which is conducive to the realization of the wafer-level preparation of multilayer materials. The potential applications of electronic and optoelectronic devices have laid the foundation.