Lateral Growth of Composition Graded Atomic Layer MoS_2(1–x)Se_2x Nanosheets

Abstract

Band gap engineering of transition-metal dichalcogenides is an important task for their applications in photonics, optoelectronics, and nanoelectronics. We report for the first time the continuous lateral growth of composition graded bilayer MoS(2(1-x))Se(2x) alloys along single triangular nanosheets by an improved chemical vapor deposition approach. From the center to the edge of the nanosheet, the composition can be gradually tuned from x = 0 (pure MoS2) to x = 0.68, leading to the corresponding bandgap being continuously modulated from 1.82 eV (680 nm) to 1.64 eV (755 nm). Local photoluminescence scanning from the center to the edge gives single band edge emission peaks, indicating high crystalline quality for the achieved alloy nanosheets, which was further demonstrated by the microstructure characterizations. These novel 2D structures offer an interesting system for probing the physical properties of layered materials and exploring new applications in functional nanoelectronic and optoelectronic devices.

In Situ Carbon-Doped Mo(Se0.85S0.15)2Hierarchical Nanotubes as Stable Anodes for High-Performance Sodium-Ion Batteries

“…This observation is in good agreement with the previous report on Mo(Se x S 1− x ) 2 alloys. [ 45,[49][50][51] The peak intensity ratio between D and G bands ( I D / I G ) of the amorphous carbon is found to increase slightly after selenization at 900 °C, probably due to the improved graphitization degree of the amorphous carbon. [ 52,53 ] An X-ray diffraction (XRD) pattern of the selenized sample is presented in Figure 1 b.…”

Booming Development of Group IV–VI Semiconductors: Fresh Blood of 2D Family

“…Ternary alloys have attracted intensive attention in recent years due to the varied properties through doping the third elements into the pure binary systems, which may provide an important versatility in low‐power consumption electronics and optoelectroncis 189, 190, 191, 192, 193, 194. For example, Pb 1–x Sn x Se is a narrow direct bandgap semiconductor with promising applications in mid‐infrared photodetection (1–3 μm), topological crystalline insulators and high‐speed logic devices due to the doping of Pb 104, 107, 195, 196.…”

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“…To date, some efforts have been made to achieve the synthesis of photoluminescent MoS2 materials and the existing approaches can be divided into three ways including exfoliation, substrate growth, and colloidal synthesis. [16][17][18][19][20] For example, Coleman et al proposed liquid-phase exfoliation of commercial MoS2 powers in a suitable organic solvent with the aid of ultrasonication as a route to prepare photoluminescent MoS2; 17 Sow and Duan et al have synthesized photoluminescent MoS2 films on various substrates using the chemical vapor deposition method. 18,19 However, the exfoliation methods or substrate growth methods had been allowed for the preparation of photoluminescent MoS 2 , inherent disadvantages limited their further applications.…”