Large Area Few-Layer Hexagonal Boron Nitride as a Raman Enhancement Material

Abstract

Increasingly, two-dimensional (2D) materials are being investigated for their potential use as surface-enhanced Raman spectroscopy (SERS) active substrates. Hexagonal Boron Nitride (hBN), a layered 2D material analogous to graphene, is mostly used as a passivation layer/dielectric substrate for nanoelectronics application. We have investigated the SERS activity of few-layer hBN film synthesized on copper foil using atmospheric pressure chemical vapor deposition. We have drop casted the probe molecules onto the hBN substrate and measured the enhancement effect due to the substrate using a 532 nm excitation laser. We observed an enhancement of ≈103 for malachite green and ≈104 for methylene blue and rhodamine 6G dyes, respectively. The observed enhancement factors are consistent with the theoretically calculated interaction energies of MB > R6G > MG with a single layer of hBN. We also observed that the enhancement is independent of the film thickness and surface morphology. We demonstrate that the hBN films are highly stable, and even for older hBN films prepared 7 months earlier, we were able to achieve similar enhancements when compared to freshly prepared films. Our detailed results and analyses demonstrate the versatility and durability of hBN films for SERS applications.

Dot-product computation and logistic regression with 2D hexagonal-boron nitride (h-BN) memristor arrays

“…Thus, to verify the quality of the h-BN film we conducted Raman spectroscopy at various randomly selected locations immediately after the transfer step. Figure 2(c) shows Raman spectra revealing peak positions at 1370 cm −1 for all different locations, consistent with previously published results on few-layer h-BN films [28]. Additional verification of the h-BN memristor structure is achieved via crosssectional transmission electron microscopy (TEM) imaging (figure 2(d)) revealing the layered nature of the h-BN film.…”

Flexible SERS substrates for hazardous materials detection: recent advances

“…Noble-metal-free SERS materials, for example semiconductors (Si, GaAs and etc.) and two-dimensional (2D) layered materials 30,31 (MoS 2 , graphene, HBN and etc.) exhibit the CM enhancement.…”

Spotting the driving forces for SERS of two-dimensional nanomaterials

“…35 Lahiri also further proved that the thickness had no impact on the SERS for the h-BN using MeB molecules. 76 The layer-independent effect of h-BN could be attributed to the high transparency in the visible range.…”