Characteristics of red emitting boron nitride nanoparticles

Abstract

Boron nitride (BN) was synthesized by pyrolysis of a molecular precursor prepared by chemical mixing of boric acid (H3BO3) and melamine (C3H6N6) with a small amount of europium nitrate (Eu3+) as luminescent materials. After pyrolysis, the Eu3+ ions were substitutionally incorporated into a B3N3 hexagonal layer of turbostratic BN (t-BN) at a low doping level estimated to be less than 12 × 1018 atoms/cm3. This phenomenon is due to a randomly stacked turbostratic structure rather than a perfectly stacked hexagonal boron nitride (h-BN) structure along the c-axis. The photoluminescence (PL) spectrum of pure BN was detected at 456 nm (blue), and Eu3+-doped BN was detected at 590, 614, 648, and 696 nm (red) by excitation of UV light (λ = 314 nm). The PL intensity improved as the level of Eu3+ addition was increased. However, excessive doping caused the disappearance of the luminescent properties due to the concentration quenching phenomenon. When the synthesized nanoparticle BN phosphor was mixed with a polymer to form a flexible composite, it was shown that it could be applied as a filter to UV-LED.