Silicon Nanosheets: An Emerging 2D Photonic Material with a Large Transient Nonlinear Optical Response beyond Graphene

Abstract

The present work reports on the transient nonlinear optical (NLO) responses of two different types of 2D silicon nanosheets (SiNSs), namely hydride-terminated silicon nanosheets (SiNS–H) and 1-dodecene-functionalized silicon nanosheets (SiNS–dodecene). The main motivation of this study was to extend the knowledge regarding the NLO properties of these Si–based materials, for which very few published studies exist so far. For that purpose, the NLO responses of SiNS–H and SiNS–dodecene were investigated experimentally in the nanosecond regime at 532 and 1064 nm using the Z-scan technique, while the obtained results were compared to those of certain recently studied graphene nanosheets. SiNS–dodecene was found to exhibit the largest third-order susceptibility χ(3) values at both excitation wavelengths, most probably ascribed to the presence of point defects, indicating the importance of chemical functionalization for the efficient enhancement and tailoring of the NLO properties of these emerging 2D Si-based materials. Most importantly, the results demonstrated that the present silicon nanosheets revealed comparable and even larger NLO responses than graphene nanosheets. Undoubtedly, SiNSs could be strong competitors of graphene for applications in 2D-material-based photonics and optoelectronics.

2D Non‐van der Waals Nanoplatelets of Hematene and Magnetene: Nonlinear Optical Response and Optical Limiting Performance from UV to NIR

“…In Table S1 the values of the NLO parameters of some other vdW 2D materials (i. e., graphene, graphene oxide, fluorographene, semiconducting (2H) and metallic (1T) transition metal dichalcogenides (MoS 2 and WS 2 ), and some hydride‐terminated silicon nanosheets (SiNS−H)) reported recently and obtained under similar experimental conditions (i. e., laser pulse duration, laser excitation wavelength, etc.) are presented [45–48] . As can be seen, the FOM values of hematene and magnetene are comparable and in some cases even larger, than those of other 2D materials, suggesting their potential for opto‐electronic and photonic applications.…”

“…are presented. [45][46][47][48] As can be seen, the FOM values of hematene and magnetene are comparable and in some cases even larger, than those of other 2D materials, suggesting their potential for opto-electronic and photonic applications.…”

Exceptional ultrafast nonlinear optical response of functionalized silicon nanosheets

“…27) and a superior nonlinear optical (NLO) response compared to graphene. 28–30 As-prepared SiNS-H can be functionalized, e.g. , via radical-induced hydrosilylation reactions with unsaturated compounds.…”

“…27) and a superior nonlinear optical (NLO) response compared to graphene. [28][29][30] As-prepared SiNS-H can be functionalized, e.g., via radical-induced hydrosilylation reactions with unsaturated compounds. 27,31 Surface functionalization might influence the optoelectronic properties [32][33][34] and prevent the nanosheets from stacking and oxidation.…”

“…27,31 Surface functionalization might influence the optoelectronic properties [32][33][34] and prevent the nanosheets from stacking and oxidation. 34 Recently, it was reported that the chemical functionalization of SiNS-H with unsaturated compounds like 1-dodecene is a powerful tool to enhance the NLO response compared to SiNS-H. [28][29][30] In particular, it was demonstrated that 1-dodecene functionalized SiNS-H, namely SiNS-dodecene, exhibits very strong saturable absorption (SA) and self-focusing behavior, promoting the high potential of SiNSs for optoelectronic and photonic applications as saturable absorbers and optical switchers. Based on these previous studies, the present work investigates the NLO responses of SiNSs functionalized with two different organic moieties.…”