Broadband Nonlinear Optical Response in Few‐Layer Antimonene and Antimonene Quantum Dots: A Promising Optical Kerr Media with Enhanced Stability

Abstract

Antimonene, a new type of 2D group‐VA material beyond phosphorene, is theoretically predicted to exhibit remarkable electronics and optical properties with enhanced stability. However, its more general and practical applications seriously lag behind due to a shortage of effective synthesis techniques in delivering high‐quality few‐layer antimonene (FLA) and antimonene quantum dots (AQDs), and deep understanding of the mechanism in light‐antimonene interaction. Herein, based on electrochemical exfoliation and sonochemical approaches, FLA is synthesized with an average thickness down to 31.6 nm and AQDs with an average lateral size of 3.4 nm, and the corresponding nonlinear optical response is further investigated at the visible wavelength for the first time. It is shown that antimonene possesses a giant nonlinear refractive index of ≈10−5 cm2 W−1 and a high stability in ambient condition for months. The experimental findings may be considered as an important step toward antimonene‐based nonlinear photonics devices (Optical Switcher, Kerr shutter, beam shaper, etc.), in which their unstable counterpart phosphorene may not compete with.

Few‐layer Bismuthene: Sonochemical Exfoliation, Nonlinear Optics and Applications for Ultrafast Photonics with Enhanced Stability

“…[54] The linear refractive index of the as-prepared suspension derived by the same method as in the literature [27] 532 nm, 633 nm and 800 nm, respectively. The phase shift ψ when a laser beam passes through the bismuthene suspension is given as…”

“…Bismuthene can be considered as a potential candidate for all optical switching and optical communication applications with enhanced stability as it can overcome limitations, such as instability and limited optical switching in the communication waveband of BP. Based on the literature, [18,27] antimonene meets the abovementioned requirement of excellent stability, while its indirect band gap might give rise to inconvenience as the conversion to its direct band-gap semiconductor could be possible under biaxial strain. [55] For bismuthene, the direct band gap is, however, an advantage in similar applications.…”

“…The SSPM explanation has been employed to investigate the intrinsic light matter interaction in atomically thin 2-D crystals, such as MoS 2 , WS 2 , [23] topological insulators, [24] MoS 2 /TiO 2 , [25] black phosphorus [26] and antimonene. [27] SSPM refers to a phenomenon in which a set of concentric circular diffraction rings merge under the illumination of high-intensity laser through a uniform thin film or bulk material. [28,29] Based on the aforementioned SSPM experiment, a calculation method for estimating the nonlinear refractive index has been deduced.…”

Noncovalent Functionalization and Charge Transfer in Antimonene

“…[4][5][6][7] This result together with its excellent charge-carrier mobility and current on/off ratios renders BP ap erfect candidate for nanoelectronics and nanophotonics.H owever,i ts (in)stability represents am ajor drawback for the development of the real applications. [8][9][10][11] In contrast, its relative in the periodic table, antimonene,that is,asingle layer of antimony,exhibits aband gap of about 1.8-2.4 eV and an outstanding stability under ambient conditions.A ntimonene has been recently isolated for the very first time both by mechanical exfoliation [12] and liquid-phase exfoliation [13] as reported by our groups.A number of theoretical calculations predict extraordinary physical properties like high carrier mobility, [14] thermal conductivity, [15] and strain-induced band transition, [16] among others.Therefore,a ntimonene appears to be ap romising platform for high-performance sensors, [17] double-gate MOSFETs, [18] spintronics, [19,20] optoelectronic applications, [21,22] energy storage and conversion, [23] and biomedicine.[24]Recently,v an der Waals and molecular beam epitaxy (MBE) have been applied for the synthesis of antimonene on different surfaces,t hereby exhibiting good stabilities and high electrical conductivities of up to 10 4 Sm À1 in about 30 nm thick flakes. [25,26] Despite synthetic efforts,t he chemistry and therefore the molecular doping of antimonene remains completely unexplored.…”

“…Therefore,a ntimonene appears to be ap romising platform for high-performance sensors, [17] double-gate MOSFETs, [18] spintronics, [19,20] optoelectronic applications, [21,22] energy storage and conversion, [23] and biomedicine.…”