Strong Ultrafast Saturable Absorption and Nonlinear Refraction of Some Non-van der Waals 2D Hematene and Magnetene Nanoplatelets for Ultrafast Photonic Applications

Abstract

In the present work, some non-van der Waals (non-vdW) 2D materials, namely, hematene and magnetene nanoplatelets, were synthesized starting from hematite and magnetite ores, respectively, using a green synthesis method, and they were dispersed in water. Then, their ultrafast nonlinear optical (NLO) response was studied under 50 fs, 400 nm laser excitation. Both non-vdW 2D materials revealed strong saturable absorption with NLO absorption coefficient β, saturable intensity, and modulation depth of about −33.2 × 10–15 m/W, 320 GW/cm2, and 19%, respectively, for hematene, and about −21.4 × 10–15 m/W, 500 GW/cm2, and 17% for magnetene. These values are comparable to those of other vdW 2D materials, such as graphene, transition metal dichalcogenides (TMDs) like MoS2, WS2, and MoSe2, black phosphorus (BP), and some MXenes (Ti3C2T x ), recently reported as efficient saturable absorbers. In addition, both hematene and magnetene dispersions displayed strong Kerr type NLO refraction with nonlinear refractive index parameters γ′ comparable and even larger than those of van der Waals 2D materials. In all cases, hematene was found exhibiting significantly larger optical nonlinearities than magnetene, most probably due to the formation of a more efficient charge transfer system. The results of the present work are strongly suggesting that hematene and magnetene can have applications in a wide range of photonic and optoelectronic applications.

Scalable solid-state synthesis of 2D transition metal oxide/graphene hybrid materials and their utilization for microsupercapacitors

“…31 Chahal et al developed a microwave-assisted synthesis of 2D MOs in dimethylformamide or isopropanol solvent using metal chlorides as precursors. 32 These 2D MOs have already been investigated for applications including catalysis, 30–33 optics, 34,35 electronics, 36,37 and sensing. 38,39 However, scalable and solid-state synthesis of 2D MO/rGO nanocomposites and their utilization in energy storage have not been demonstrated before.…”

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

“…[28] Their ultrafast NLO response has been investigated, for the first time to the best of our knowledge, under 50 fs laser excitation. Both studied hematene and magnetene nanoplatelets were found to reveal strong saturable absorption and self-focusing action, [29] thus raising their high potential for photonics and optoelectronics. In addition, in a recent work, it was reported that hematene nanosheets exhibit strong RSA response under ns, 532 nm laser excitation giving rise to very efficient optical limiting.…”

“…[21] Initial application-oriented research efforts has revealed that non-vdW 2D materials are promising candidates for electrocatalysis, [22,23] energy storage, [24] and magnetophotoconductivity. [25] In addition, since non-vdW 2D materials display high carrier mobility, [26] tunable energy bandgap through facile surface modification due to the abundance of dangling bonds, [27] and superior nonlinear optical (NLO) response than their van der Waals 2D counterparts, [28][29][30] it is speculated that they could find numerous applications in photonics and optoelectronics.…”

Insights into the Unanticipated Chemical Reactivity of Functionalized Nanosheets Derived from TiB2

“…The past decade has witnessed a rapid realization of two-dimensional (2D) materials from non-van der Waals layered materials. − This research effort has been driven to a large extent by the unique properties that these materials possess and also the exciting prospect of exploring lesser-known interfaces as exemplified in the case of MXenes, metallenes, 2D metal oxides, and many others.…”