Hydrogen passivation effect on the sealing problem of edge growth in h-BN

Edge kinetics in two dimensional structure has been the key to understand the growth. In this talk, we’ll illustrate the intrinsic difficulty to fill out the last few atoms to the edge of hexagonal BN and define such a difficulty as a sealing problem. The physical origin is due to the accumulation of local strain energy of the reconstruction near edges. Specifically, the local distortion becomes severe when more atoms are imperfectly placed to fill the gap on the edge. To solve the sealing problem and reduce the energy barrier to form a perfect edge, it’s possible to passivate the dangling bonds of the edge atoms to reduce the edge reconstruction by hydrogen. This new finding and growth strategy may largely enhance the crystal quality and growth rate.