Recent progress of structures and photoelectric properties of two-dimensional materials under high pressure
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-01 |
| Journal | Acta Physica Sinica |
| Authors | CHENG Lingying, Huafang Zhang, Yanli Mao |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis paper reviews the use of high-pressure (HP) engineering to modulate the structure and photoelectric properties of two-dimensional (2D) materials (Graphene, TMDs, and Perovskites).
- Core Value Proposition: HP is an efficient, clean, and continuous tuning method that reveals intrinsic structure-property correlations in 2D materials without introducing chemical impurities.
- Structural Control: HP effectively compresses atomic distances, strengthens interlayer coupling (Van der Waals forces), and induces structural phase transitions (e.g., h-BN to w-BN, Td to 1Tâ in WTe2).
- Bandgap Engineering: Pressure drives fundamental electronic transitions, including the semimetal-to-semiconductor transition in graphene (opening a bandgap up to 2.5 eV) and semiconductor-to-metal transitions in TMDs (MoS2, Ti3C2Tx).
- Superconductivity: HP successfully induces superconductivity in ReS2 above 90 GPa, demonstrating its potential for creating novel quantum materials.
- Optical Performance Enhancement: HP significantly enhances photoluminescence (PL) efficiency (up to 8-12 times) in 2D metal halide perovskites and g-C3N4 by suppressing non-radiative recombination pathways.
- Anisotropic Effects: The unique layered structure leads to highly anisotropic compression, where layer-to-layer distance changes often dominate electronic property modulation at low pressures.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Graphene SC Bandgap | 2.5 ± 0.3 | eV | Max bandgap opening in few-layer graphene (SC: Semiconducting). |
| Graphene sp2-sp3 Transition | 19.4 to 28.3 | GPa | Pressure range depending on layer count (12-layer to trilayer). |
| VC-Graphene Bandgap Tunability | 0 to 260 | meV | Tunable range achieved via pressure engineering. |
| MoS2 SC-Metal Transition | 10 to 19 | GPa | Pressure range for 3-order-of-magnitude resistivity drop (multilayer). |
| ReS2 Superconductivity Tc | 2.5 | K | Critical temperature achieved at 102.0 GPa. |
| WTe2 Phase Transition (Td to 1Tâ) | 6.0 | GPa | Pressure required for structural transition. |
| (PEA)2PbI4 Bandgap Narrowing | 1.25 | eV | Achieved at 27.5 GPa (approaching Shockley-Queisser limit of 1.33 eV). |
| (BA)2PbI4 Resistance Change | 10,000 | times | Resistance decrease at 34 GPa (SC-M transition). |
| (BA)4AgBiBr8 PL Enhancement | 8 | times | Max PL intensity increase at 8.2 GPa. |
| Ti3C2Tx SC-Metal Transition | 6.6 | GPa | Confirmed by variable-temperature resistance test. |
| g-C3N4 PL Enhancement | 8 | times | Max PL intensity increase at 2.1 GPa. |
| h-BN Phase Transition (h-BN to w-BN) | 13 | GPa | Pressure required for irreversible phase change. |
| h-BN PL Peak Shift | 14.1 ± 0.2 | meV/GPa | Positive pressure coefficient for blue-shifted PL peaks. |
Key Methodologies
Section titled âKey MethodologiesâThe research relies heavily on the Diamond Anvil Cell (DAC) combined with multimodal in situ characterization techniques:
- High-Pressure Generation: Diamond Anvil Cell (DAC) devices are used to generate pressures up to hundreds of GPa by compressing samples between two diamond anvils.
- Pressure Calibration:
- Ruby Fluorescence Method: Measures the shift of the R-line fluorescence wavelength of ruby crystals embedded near the sample.
- Diamond Raman Method: Measures the shift of the diamond phonon mode, typically used for pressures > 30 GPa.
- Pressure Medium Selection:
- Quasi-Hydrostatic Conditions: Achieved using liquid or gaseous media (e.g., Methanol-Ethanol 4:1, He, Ne, Ar) to ensure uniform pressure distribution, critical for sensitive 2D materials.
- Structural Analysis (In Situ): Synchrotron X-ray Diffraction (XRD) is employed to monitor changes in crystal structure, lattice constants (a, c), and phase transitions under compression.
- Vibrational and Phonon Analysis (In Situ): Raman Spectroscopy tracks the evolution of phonon modes (e.g., E2g, A1g) to identify structural distortion, strain, and phase changes.
- Optoelectronic Characterization (In Situ):
- Photoluminescence (PL) Spectroscopy: Measures emission intensity and peak shifts to track bandgap evolution and exciton dynamics.
- UV-Vis Absorption Spectroscopy: Determines bandgap energy (Eg) and absorption coefficients under pressure.
- Electrical Transport Measurements: Measures resistance and photoconductivity as a function of pressure and temperature to identify semiconductor-to-metal transitions and superconductivity.
Commercial Applications
Section titled âCommercial ApplicationsâThe ability to precisely tune the properties of 2D materials using pressure engineering opens pathways for several advanced technological applications:
- Advanced Electronics and Switching Devices:
- Development of high-performance switching devices utilizing the sharp semiconductor-to-metal transitions observed in TMDs (MoS2, Ti3C2Tx) under moderate pressure.
- Graphene-based electronics where pressure can open a bandgap, enabling its use in transistors (VC-Graphene).
- Energy Conversion (Photovoltaics):
- Designing highly efficient solar cells using 2D perovskites, leveraging pressure-induced bandgap narrowing to match the optimal Shockley-Queisser limit (around 1.33 eV).
- Light Emitting Devices (LEDs):
- Creation of stable, high-efficiency, warm-white light sources using pressure-treated 2D metal halide perovskites, suitable for general lighting applications.
- Quantum Computing and Low-Temperature Electronics:
- Exploiting pressure-induced superconductivity in materials like ReS2 for developing novel superconducting components and platforms for quantum information science.
- Sensing and Actuators:
- Utilizing the high pressure-sensitivity of PL intensity in materials like g-C3N4 for developing highly responsive pressure sensors and transducers.
- Energy Storage (Batteries/Supercapacitors):
- Optimizing the electronic transport properties of MXene (Ti3C2Tx) electrode materials through pressure treatment to enhance charge carrier mobility and storage capacity.
View Original Abstract
Two-dimensional (2D) materials, due to their outstanding photoelectric properties, have demonstrated significant potential in both fundamental scientific research and future technological applications, including optoelectronics, energy storage, and conversion devices, establishing them as a cutting-edge research field in condensed matter physics and materials science. The distinctive layered structure of 2D materials renders their physical properties highly sensitive to external stimuli. High-pressure technology, serving as an efficient, continuous, and clean tuning tool, enables precise structural control and optimization of the photoelectric properties of 2D materials by compressing atomic distances, strengthening interlayer coupling, and even inducing structural phase transitions. This article focuses on prototypical two-dimensional materials, including graphene, transition metal dichalcogenides (TMDs), and two-dimensional metal halide perovskites. Employing the diamond anvil cell combined with multimodal <i>in situ</i> high-pressure characterization techniques such as X-ray diffraction, Raman spectroscopy, photoluminescence, and electrical transport measurements, we systematically elucidate the effects of high pressure on the structural and photoelectric properties of these materials. The key findings indicate that high pressure can induce the graphene to transition from a semimetal state to a semiconducting state, even a superconducting state, triggering off structural phase transitions and semiconductor-to-metal transitions in TMDs such as MoS<sub>2</sub> and WTe<sub>2</sub>, and leading to a pressure-dependent bandgap narrowing and significant enhancement of luminescence intensity in two-dimensional perovskites. This work highlights the utility of high-pressure techniques in revealing the intrinsic correlations between the microstructure and macroscopic properties of two-dimensional materials. Furthermore, it discusses the key challenges and opportunities in this emerging research area, providing insights into the development and practical application of novel functional materials.