Impact Factor:13.903
Journal:ACS Nano
Key Words:hexagonal boron nitride flakes, single photon emissions, deep-level defects, photoluminescence, hydrostatic pressure
Abstract:Research on hexagonal boron nitride (hBN) has been intensified recently due to the application of hBN as a promising system
of single-photon emitters. To date, the single photon origin remains under debate even though many experiments and theoretical calculations have been performed. We have measured the pressure-dependent photoluminescence (PL) spectra of hBN flakes at low temperatures by using a diamond anvil cell device. The absolute values of the pressure coefficients of discrete PL emission lines are all below 15 meV/GPa, which is much lower
than the pressure-induced 36 meV/GPa redshift rate of the hBN bandgap. These PL emission lines originate from atom-like localized defect levels confined within the bandgap of the hBN flakes. Interestingly, the experimental results of the pressure-dependent PL emission lines present three different types of pressure responses corresponding to a redshift (negative pressure coefficient), a blueshift (positive pressure coefficient), or even a sign change from negative to positive. Density functional theory calculations indicate the existence of competition between the intralayer and interlayer interaction contributions, which leads to the different pressure-dependent behaviors of the PL peak shift.
Indexed by:Journal paper
Discipline:Natural Science
First-Level Discipline:Physics
Volume:12
Page Number:7127−7133
Translation or Not:no
Included Journals:SCI
Date of Publication:2018-06-29