Hexagonal boron nitride hollow capsules with collapsed surfaces: Chemical vapor deposition with single-source precursor ammonium fluoroborate
Li Xiaopeng1, Zhang Jun1, Yu Chao1, Liu Xiaoxi1, Abbas Saleem1, Li Jie1, Xue Yanming2, †, 
, Tang Chengchun1, ‡,
, Tang Chengchun1, ‡, Schematic diagram of the CVD system of NH4BF4: (a) the system in the heating-up stage; (b) the system in the stable target-temperature stage.
