Related Experiment Video
Updated: Mar 9, 2026

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Structural Phase Transition and Material Properties of Few-Layer Monochalcogenides
Mehrshad Mehboudi1, Benjamin M Fregoso2, Yurong Yang1
1Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA.
Few-layer group-IV monochalcogenides exhibit a 2D phase transition, altering electronic and optical properties. Temperature acts as a control knob for these semiconducting materials, impacting their unique characteristics.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid-State Physics
Background:
- Group-IV monochalcogenides like GeSe and SnSe are promising 2D materials.
- These materials are known for potential ferroelectric and piezoelectric properties.
Purpose of the Study:
- To investigate the 2D phase transition in GeSe and SnSe monolayers and bilayers.
- To understand the impact of this transition on material properties, including electronic, spin, optical, and piezoelectric characteristics.
Main Methods:
- Car-Parrinello molecular dynamics simulations.
- Density-functional theory calculations.
Main Results:
- A critical temperature (Tc) induces a phase transition from rectangular to square unit cells.
- Materials remain semiconducting, with no in-gap states forming.
- Electronic band structure, spin polarization, optical absorption, and piezoelectricity are significantly altered at Tc.
- An anomalous thermal increase in hole conductivity is predicted.
Conclusions:
- Temperature is a crucial control parameter for tuning the physical properties of few-layer group-IV monochalcogenides.
- The structural transition at Tc leads to a symmetric electronic structure and modified material responses.
- Predicted pyroelectric response of approximately 3×10⁻¹² C/K·m.
More Related Videos
10:41Preparation of Liquid-exfoliated Transition Metal Dichalcogenide Nanosheets with Controlled Size and Thickness: A State of the Art Protocol
Published on: December 20, 2016
08:50Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication
Published on: November 28, 2017
Related Concept Videos
Phase Transitions: Sublimation and Deposition
Phase Transitions
Phase Transitions
Phase Diagram
Phase Diagrams
Phase Transitions: Vaporization and Condensation