Figure 4
Selective hydrogen etching to reveal the defects and boundaries of h-BN.
(a) is the OM image of h-BN domain with a triangle-shape hole in, after hydrogen etching; (b) to (d) are the OM images of complex-shape of h-BN domains with gap between neighboring parts, after hydrogen (20 sccm) etching, the inset images show the complex-shape h-BN domains have complete shape before hydrogen etching; (e) to (h) are the OM images of triangle-shape h-BN domain growth under 20 hydrogen gas flow with different growth time, varying from 10 minutes, 20 minutes, 40 minutes to 60 minutes; (i) to (l) are the OM images that show hydrogen etching on the complete fully covered h-BN film from (h) with different etching time of 5 minutes, 20 minutes, 50 minutes and 80 minutes and the inset image in (j) is the corresponding FFT image. The scale bars in (a) to (d) are 10 μm and in (e) to (l) are 40 μm.
