Controlled Growth and Thickness‐Dependent Conduction‐Type Transition of 2D Ferrimagnetic Cr₂S₃ Semiconductors

TLDR

Two‑dimensional magnetic materials are promising for multifunctional electronic and spintronic devices, yet most are produced by mechanical exfoliation and direct, thickness‑controlled synthesis remains rare. The authors aim to demonstrate thickness‑tunable synthesis of nanothick rhombohedral Cr₂S₃ flakes on mica via chemical vapor deposition. They achieve this by precisely controlling the Cr precursor feeding rate and growth temperature during CVD. The work reveals that Cr₂S₃ conduction shifts from p‑type to ambipolar to n‑type as thickness increases, underscoring its potential for scalable synthesis and exploration of transport and magnetic properties.

Abstract

2D magnetic materials have attracted intense attention as ideal platforms for constructing multifunctional electronic and spintronic devices. However, most of the reported 2D magnetic materials are mainly achieved by the mechanical exfoliation route. The direct synthesis of such materials is still rarely reported, especially toward thickness-controlled synthesis down to the 2D limit. Herein, the thickness-tunable synthesis of nanothick rhombohedral Cr2 S3 flakes (from ≈1.9 nm to tens of nanometers) on a chemically inert mica substrate via a facile chemical vapor deposition route is demonstrated. This is accomplished by an accurate control of the feeding rate of the Cr precursor and the growth temperature. Furthermore, it is revealed that the conduction behavior of the nanothick Cr2 S3 is variable with increasing thickness (from 2.6 to 4.8 nm and >7 nm) from p-type to ambipolar and then to n-type. Hereby, this work can shed light on the scalable synthesis, transport, and magnetic properties explorations of 2D magnetic materials.