Effects of deformation on band-edge luminescence of hexagonal boron nitride single crystals

The authors observed a drastic change in exciton-related luminescence in deformed hexagonal boron nitride single crystals. High quality single crystals that showed a free exciton luminescence band at 215 nm were used as a starting material. They were pinched between aluminum plates and pressed with the tips of the first two fingers. The pressed crystals dominantly showed band-edge luminescence at the 227 instead of the 215 nm band. The authors attribute this 227 nm band to bound exciton luminescence caused by the stacking disorder produced by the mechanical deformation. (c) 2006 American Institute of Physics.