Solution Processing for Lateral Transition-Metal Dichalcogenides Homojunction from Polymorphic Crystal

Abstract

Homojunctions comprised of transition-metal dichalcogenides (TMD) polymorphs are attractive building blocks for next-generation two-dimensional (2D) electronic circuitry. However, the synthesis of such homojunctions, which usually involves elaborate manipulation at the nanoscale, still remains a great challenge. Herein, we demonstrated a solution-processing strategy to successfully harvest lateral semiconductor–metal homojunctions with high yield. Specially, through precisely controlled lithiation process, precursors of polymorphic crystal arranged with 1T–2H domains were successfully achieved. A programmed exfoliation procedure was further employed to orderly laminate each phase in the polymorphic crystal, thus leading to 1T–2H TMD homojunction monolayers with sizes up to tens of micrometers. Moreover, the atomically sharp boundaries and superior band alignment improved the device on the basis of the semiconductor–metal homojunction with 50% decrease of electric field strength required in the derivation of state transition. We anticipate that solution processing based on programmed exfoliation would be a powerful tool to produce new configurations of 2D nanomaterials.

Structure, Preparation, and Applications of 2D Material‐Based Metal–Semiconductor Heterostructures

“…[89] The mechanism was explained by the electron transfer from alkali metal to MoS2 increasing the stability of the metallic phase of MoS2, and also significantly decreasing the kinetic energy barrier for the phase transition. [90] By precisely controlling the intercalation process, metallicsemiconducting 1T (or 1T')-2H MoS2 [91][92] and 2H-1T TaS2 [93] homostructures were prepared by chemically exfoliating the corresponding bulk materials. To enhance the spatial controllability of the ion intercalation process, it could be directly performed on 2D flakes located on a certain substrate (like the CVD samples), combined with patterning techniques like e-beam lithography.…”

A Hybrid Artificial Photocatalysis System Splits Atmospheric Water for Simultaneous Dehumidification and Power Generation

“…Systems based on ferroelectric–semiconductor, typically requiring an external energy for polarization pretreatment, also suffers from a limitation of degeneration with the polarized built‐in electric field over time . “Crystal plane engineering” is an efficient method for exposing different crystal planes in a nanoparticle, which aids in achieving difference surface potentials at various planes ascribed to the varied atomic arrangements . Using this strategy, a polarizing electric field can be induced between crystal planes.…”

Surface/Interface Chemistry Engineering of Correlated‐Electron Materials: From Conducting Solids, Phase Transitions to External‐Field Response

“…[ 34,35 ] To this end, 1T‐2H‐TaS 2 homojunction monolayers were successfully fabricated via a solution‐process method ( Figure a). [ 36 ] Through precise control of the lithiation procedure for 1T‐TaS 2 crystals, 1T phase maintained at low Li content, whereas converted to metallic 2H‐TaS 2 phase at high Li content regions. 1T‐2H‐TaS 2 homojunction monolayers can be obtained by a programmed exfoliation of this polymorphic crystals with 1T and 2H phases using H 2 O and acids.…”

“…Reproduced with permission. [ 36 ] Copyright 2019, American Chemical Society. b) Schematic structure of the TaS 2 −N 2 H 4 hybrid superlattice.…”