Localized emission from laser-irradiated defects in 2D hexagonal boron nitride

Abstract

Hexagonal boron nitride (hBN) has emerged as a promising two-dimensional (2D) material for photonics device due to its large bandgap and flexibility in nanophotonic circuits. Here, we report bright and localized luminescent centres can be engineered in hBN monolayers and flakes using laser irradiation. The transition from hBN to cBN emerges in laser irradiated hBN large monolayers while is absent in processed hBN flakes. Remarkably, the colour centres in hBN flakes exhibit room temperature cleaner single photon emissions with g2(0) ranging from 0.20 to 0.42, a narrower line width of 1.4 nm and higher brightness compared with monolayers. Our results pave the way to engineering deterministic defects in hBN induced by laser pulse and show great prospect for application of defects in hBN used as nano-size light source in photonics.

Light–Matter Interaction of Single Quantum Emitters with Dielectric Nanostructures

“…The resulting defects exhibit a broad range of multicolor single photon emission at room temperature across the visible and near-infrared spectral ranges, with narrow line widths of~10 nm, short excited-state lifetime and high brightness. Laser ablation technique was also recently reported to be able to engineer bright color centers in hBN monolayers and multilayers [43], where the color centers in hBN monolayers and multilayers exhibit single photon emissions with linewidths of 4.5 nm and 1.4 nm, respectively, narrower than that of~10 nm from defects created by electron beam irradiation mentioned above; see Figure 3c,d. At cryogenic temperature, the lifetime and first-order measurements showed ultrafast spectral diffusion in hBN, whereas the photon coherence time is still less than the lifetime of the emitter in hBN, causing inhomogeneous broadening of the line [44].…”

“…The similar polarizations of the excitation and the emission in Figure 3b show single linearly polarized dipole transition, indicating that the emission center consists of a single dipole. Different approaches for engineering quantum emitters in hBN layers were developed, i.e., annealing, electron beam irradiation [42], and laser ablation [43]. In the annealing method, defect diffusion and lattice relaxation occur in the as-grown hBN flakes, as annealing temperature increases in an inert environment.…”

Grain-boundary-rich 2D materials for attomolar-ability biochemical sensors

“…Mechanical exfoliation is a simple and low-cost technique to obtain high-quality, surface-clean, few-layer 2D akes with uncontrollable size, shape and thickness; and the preferred high-throughput defects can be created via post-treatment defect engineering methods, like plasma, ion/electron beam and laser irradiation. [28][29][30][31][32][33][34][35][36][37][38] However, the di culty in scalable production of large-scale few-layer 2D akes render mechanical exfoliation infeasible in practical applications. Liquid-phase exfoliation is a high-yield method to produce 2D crystals with non-uniform size, shape and thickness.…”

Study of Thermal Effect in the Interaction of Nanosecond Capillary Discharge Extreme Ultraviolet Laser with Copper

“…Until now, various methods were explored to break the diffraction limitation, such as metalenses, e.g., Hence, micro/nanostructures were created in the interaction of laser with solid targets. For example, during the interaction of the laser with matters, nanoparticles could be formed with luminescent or plasmonic properties [1][2][3], especially copper plasmonic nanoparticles [4]. Among all the methods for creating small scale structures on various surfaces by lasers, decreasing the laser wavelength is still the most direct way [5,6].…”