Facile Two‐Step van der Waals Epitaxial Growth of Bi₂S₃/ReS₂ Heterostructure with Improved Saturable Absorption

Abstract

and modulation depth (MoS 2 ≈ 12.7%) [7] in the early time. Different from group-VI TMDs, ReS 2 as a group-VII TMDs is a direct bandgap (≈1.5 eV) semiconductor in both monolayer and bulk crystal. [8] Meanwhile, ReS 2 demonstrates high stability, reasonable carrier mobility (≈30 cm 2 •V −1 s −1 ), [9] and high current on/ off ratio (≈10 6 ). [8] However, ReS 2 shows poor NLO response such as low SA coefficients (−5.99 cm GW −1 ) [1] and modulation depth (≈3%), [10] which severely hinders its application in ultrafast laser. [6,11] Recently, some 2D ReS 2 based van der Waals (vdW) heterostructures such as ReS 2 /MoS 2 , [12] ReS 2 /ReSe 2 , [13] ReS 2 /WSe 2 , [14] and ReS 2 / Graphene [15] have been constructed to improve linear optoelectronic devices [16] such as photodetectors, field-effect transistors, and solar cells, owing to their synergistic effect in the heterostructures. However, few NLO experiments have been demonstrated in ReS 2 based heterostructures. The influence of band alignment on NLO response still need to be unveiled.Bi 2 S 3 can be an elementary component for vdW heterostructure due to its high figure of merit (FOM ≈6.17 × 10 −14 esu cm), [17] environmental stability, excellent absorption coefficient (≈10 5 cm −1 ), [18] and tunable bandgap (from 1.28 to 1.84 eV [19][20] ). Furthermore, Bi 2 S 3 demonstrates relatively high SA coefficient (−63.38 cm GW −1 ) [17] and modulation depth (≈5.7%). [21] Complementarity in Bi 2 S 3 and ReS 2 would promise the heterostructure of Bi 2 S 3 and ReS 2 for "one plus one greater than two" NLO properties. Unlike traditional bonded heterostructures, these 2D vdW heterostructures can be easily integrated without lattice-matching limitation. [22] However, most vdW heterostructures are constructed by mechanical stacking or physical transfer process, which are not scalable for practical applications. [23] Besides, early methods may result in uncontrollable stacking orientation and unavoidable contamination in the transfer process. [24] Some recent reports of two-step vdW vapor epitaxial growth provide an opportunity towards scalable integration of 2D materials. [25,26] Importantly, the vdW vapor epitaxial growth shows the advantages: (I) efficient control in size and convenient growth in scale; (II) atomic uniformity at the interface; (III) layer-by-layer formation without alloys; (IV) compatibility with the current industrial technology. Even though Sb 2 Se 3 /WS 2 , [27] Bi 2 S 3 /MoS 2 , [28] and SnSe 2 /MoS 2 [24] have been successfully demonstrated by vdW vapor epitaxial growth, there is no report on the Bi 2 S 3 /ReS 2 , to our best knowledge. 2D van der Waals (vdW) heterostructure provides a novel platform to modulate linear and nonlinear optical (NLO) properties for optical devices by interface engineering. However, NLO properties and mechanisms based on vdW heterostructures are far from complete understanding. Herein, two-step vdW vapor epitaxial growth by either physical or chemical vapor deposition methods is successfully demonstrated to synthesize unifor...

Two dimensional NbSe2/Nb2O5 metal–semiconductor heterostructure-based photoelectrochemical photodetector with fast response and high flexibility

“…After the formation of the Nb 2 O 5 /NbSe 2 heterostructure, the binding energy of the O 1s peak has a relative shift towards higher binding energy. These shifts can be explained by the efficient charge transfer from Nb 2 O 5 to Nb 2 Se 5 , which is also found in 2D Bi 2 S 3 /ReS 2 , 38 SnSe 2 /SnSe 39 and SnS/SnSe 2 40 heterostructures.…”

Direct Z‐Scheme Heterostructure of Vertically Oriented SnS2 Nanosheet on BiVO4 Nanoflower for Self‐Powered Photodetectors and Water Splitting

“…These peak shifts may come from the interfacial charge redistribution and transportation, which is frequently seen in heterostructures. [ 35 ] Due to the dielectric screening and interlayer coupling effect, which are responsible for interlayer charge redistribution in heterostructures. Ultraviolet–visible (UV–vis) spectroscopy is conducted to investigate optical properties of the as‐prepared samples, as presented in Figure 2c.…”

Study on interface engineering and chemical bonding of the ReS2@ZnO heterointerface for efficient charge transfer and nonlinear optical conversion efficiency

“…It can be widely used in ultrafast lasers. 33 The dynamic time of photo-generated carrier transport can be used to evaluate the mass of the V Re -ReS 2 @ZnO heterostructure, 30 so the TA measurement was carried out for the V Re -ReS 2 and V Re -ReS 2 @ZnO heterostructure. Fig.…”

“…Due to the complementary effect of heterostructures, it is used to improve linear optoelectronic devices, such as photodiodes, 30 solar cells, 32 and many other fields. C. Lu et al 33 successfully synthesized a large area of Bi 2 S 3 /ReS 2 heterostructure films by using the two-step van der Waals epitaxial growth method. Compared with pure ReS 2 , the heterostructure has excellent nonlinear optical performance such as a higher SA coefficient, greater modulation depth, and lower saturation strength.…”