Two-dimensional transition metal dichalcogenide alloys: preparation, characterization and applications

Abstract

Engineering electronic structure of atomically thin two-dimensional (2D) materials is of great importance to their potential applications. In comparison to numerous other approaches, such as strain and chemical functionization, alloying can continuously tune the band gaps in a wide energy range. Atomically thin 2D alloys have been prepared and studied recently due to their potential use in electronic and optoelectronic applications. In this review, we first summarize the preparation methods of 2D alloys (mainly on transition metal dichalcogenide (TMD) monolayer alloys), including mechanical exfoliation, physical vapor deposition (PVD), chemical vapor deposition (CVD) and chalcogen exchange. Then, atomic-resolution imaging, Raman and photoluminescence (PL) spectroscopy characterization of 2D alloys are reviewed, in which band gap tuning is discussed in detail based on the PL experiments and theoretical calculations. Finally, applications of 2D alloys in field-effect transistors (FETs), photocurrent generation and hydrogen evolution catalysis are reviewed.

Interlayer Nanoarchitectonics of Two‐Dimensional Transition‐Metal Dichalcogenides Nanosheets for Energy Storage and Conversion Applications

“…[1][2][3][4][5] Owing to their high anisotropy and unique crystal structures, MX 2 can be utilized in a variety of energy conversion and storage applications, including water splitting cells, rechargeable batteries, supercapacitors, fuel cells, as well as various electronic and optoelectronic devices, etc. [6][7][8][9][10][11] Nanoengineering (morphology, size, number of layers, edges, defects), [12][13][14][15][16][17] phase conversion, [18][19][20][21][22][23] and composition tuning (alloying, doping with foreign transition metal), [24][25][26][27][28][29][30][31] represent the hot research areas in the recent past, aiming at modulation of the material properties and improvement of the device performances. Such impressive progress benefits from the success in synthesizing nanostructured MX 2 with precisely controlled parameters including edge density and crystalline phase.…”

Band Gap Engineering of Hybrid 2-D Nanomaterials Some Recent Developments

“…binary, ternary, quaternary and so on) using alloying of constituent crystalline compounds with matching lattice constants has already been explored in past facilitating their applications in numerous electronic/optoelectronic devices to a large extent [1]. Drawing a parallel from there motivated to try similar attempts in atomically thin 2D semiconductor monolayers to grow materials with tunable band gaps for their applications in several functional devices [1,[32][33][34][35][36][37][38][39][40][41].…”

Strain‐Induced Structural Deformation Study of 2D MoxW(1‐x) S2

“…[4][5][6][7][8][9][10][11][12][13][14][15][16] However, alloying introduces a significant level of intrinsic strain in the structure due to the mismatch in the lattice parameters. Recently, many TMD alloys in the form of M x N (1-x) X 2 and MX y Y (1-y) (where M, N: Mo, W, Re X: S, Se, Te, 0 < x, y < 1) have been synthesized by chemical vapor deposition (CVD), chemical vapor transport (CVT), and wet chemical.…”

“…Recently, many TMD alloys in the form of M x N (1-x) X 2 and MX y Y (1-y) (where M, N: Mo, W, Re X: S, Se, Te, 0 < x, y < 1) have been synthesized by chemical vapor deposition (CVD), chemical vapor transport (CVT), and wet chemical. [4][5][6][7][8][9][10][11][12][13][14][15][16] However, alloying introduces a significant level of intrinsic strain in the structure due to the mismatch in the lattice parameters. This strain can have a crucial role in designing flexible devices.…”