Germanium Diselenide (GeSe2) Powder and Crystals

Germanium diselenide (GeSe₂) belongs to the group IV layered transition metal dichalcogenides (TMDCs). 2D GeSe₂ with a direct wide bandgap (2.74 eV) is of great research interest for its potential applications in ultraviolet (UV) detection. Compared to the bulk structure, the monolayer GeSe₂ exhibits the small average effective mass and significant anisotropy in optical absorption, indicating potential optoelectronic applications Photodetectors based on GeSe₂ exhibit a highly polarization-sensitive photo response in short wave region due to the optical absorption anisotropy induced by in-plane anisotropy in crystal structure.

Exfoliated GeSe₂ nanoflakes also show great stability in ambient air.

We supply low price germanium diselenide in several different forms for a range of applications.

Germanium Diselenide Powder

Can be used for preparation of germanium diselenide nanoplates and ultrathin films

Sold by weight

≥99.995% purity

From £200

Germanium Diselenide by Size

Can be used to produce single or few-layer germanium diselenide sheets via mechanical or liquid exfoliation

Small (≥10 mm²) or medium (≥25 mm²) crystals available*

≥99.999% purity

From £620

*Typical representative size, areas/dimensions may vary

Bulk single germanium diselenide crystal is most commonly used as sources from which single or few-layer sheets can be obtained via either mechanical or liquid exfoliation. 

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Germanium diselenide powder can also be used to prepare GeSe₂ nanosheets and nanoparticles by liquid-exfoliation (normally assisted by sonication). 

Key Product Data

• High purity, low price Germanium diselenide
• Available as a powder or as individual crystals
• Can be used to produce single or few-layer sheets
• Free worldwide shipping on qualifying orders

Structure of Germanium Diselenide

GeSe₂ crystallizes in the tetragonal I-42d space group. The structure is two-dimensional and consists of two GeSe₂ sheets oriented in the (0, 0, 1) direction. Ge⁴⁺ is bonded to four equivalent Se^2- atoms to form corner-sharing GeSe₄ tetrahedra. All Ge–Se bond lengths are 2.40 Å. S^2- is bonded in a water-like geometry to two equivalent Ge⁴⁺ atoms.

Tetragonal GeSe₂ is considered a structure of high symmetry: a GeSe₂ monolayer in which all tetrahedra are connected via corners, resulting in a much more ordered arrangement. This structure corresponds to a single slab of the high-pressure, layer-structured, tetragonal HgI₂-type phase.

Properties of Germanium Diselenide

After exfoliation of crystals or powder, germanium disulfide typically has the following properties:

• Group IV layered metal dichalcogenides
• Tetragonal (HgI₂-type) crystal structure (Space group P4_2/nmc)
• Strong in-plane anisotropy
• Great candidate for both UV detection and energy storage

Germanium Diselenide Applications

Germanium diselenide single crystals can be used to prepare monolayer and few-layer GeSe₂ by mechanical or liquid exfoliation. Germanium diselenide powder is suitable for liquid chemical exfoliation to prepare GeSe₂ nanosheets and nanoparticles down to few-layer films. 

2D GeSe₂ is a promising candidate for highly selective polarization-sensitive UV detection and electrode material for batteries in energy storage devices.

Germanium diselenide (GeSe₂), a 2D layered metal dichalcogenide with a direct wide bandgap (2.96 eV), is of great interests for its potential applications in ultraviolet (UV) detection due to its excellent workability in the short-wave region. Photo-field effect transistors based on the GeSe₂ monolayer show p-type behaviour, high responsivity, superior detectivity, and a fast response time, competitive with state-of-the-art UV detectors

Exhibiting perpendicular optical reversal of the linear dichroism and polarized photodetection under wavelength modulation, 2D GeSe₂ is a promising candidate for highly selective polarization-sensitive UV detection.

GeSe₂ has also attracted wide attentions due to its distinctive in-plane anisotropic properties originated from the in-plane anisotropic crystal structure, high air stability and excellent performance in polarization-sensitive photodetection. It has been reported that electronic band structure and effective mass of charge carriers are highly sensitive to strains. The strain-engineering properties of GeSe₂ give the rise of its applications in novel mechanical-electronic.

Intercalated GeSe₂ can also be used for energy storage devices.

Processing Germanium Diselenide

Viscoelastic transfer using PDMS

Literature and Reviews

• Ab initio molecular-dynamics study of the structural, vibrational, and electronic properties of glassy GeSe2, M. Cobb et al., Phys. Rev. B, 54 (17), 12162 (1996); DOI: 10.1103/PhysRevB.54.12162.
• Structural and electronic properties of glassy GeSe2 surfaces, X. Zhang et al., Phys. Rev. B, 62 (23), 15695 (2000); DOI: 10.1103/PhysRevB.62.15695.
• Three-Dimensional Hierarchical GeSe2 Nanostructures for High Performance Flexible All-Solid-State Supercapacitors, X. Wang et al., Adv. Mater., 25 (10), 1479-1486 (2013); DOI: 10.1002/adma.201204063.
• Air-Stable In-Plane Anisotropic GeSe2 for Highly Polarization-Sensitive Photodetection in Short Wave Region, Y. Yang et al., J. Am. Chem. Soc. 2018, 140, 11, 4150–4156 (2018); DOI: 10.1021/jacs.8b01234.
• Weak Interlayer Interaction in 2D Anisotropic GeSe2, Y. Yang et al., Adv. Sci., 6, 1801810 (2019); DOI: 10.1002/advs.201801810.
• Strain-engineering the electronic properties and anisotropy of GeSe2 monolayers, RSC Adv., 8, 33445 (2018); DOI: 10.1039/c8ra06606j.
• Defects in a Disordered World: The Structure of Glassy GeSe2, I. Petri et al., Phys. Rev. Lett., 84 (11), 2413-2416 (2000); DOI:10.1103/PhysRevLett.84.2413.
• Ultrafast light induced unusually broad transient absorption in the sub-bandgap region of GeSe2 thin film, A. Barik et al., Sci. Rep., 4, 3686 (2013); DOI: 10.1038/srep03686.
• Short-range order of compressed amorphous GeSe2, L. Properzi et al., Sci. Rep., 4, 10188 (2014); DOI: 10.1038/srep10188.
• Ultrathin 2D GeSe2 Rhombic Flakes with High Anisotropy Realized by Van der Waals Epitaxy, X. Zhou et al., Adv. Funct. Mater., 1703858 (2017); DOI: 10.1002/adfm.201703858.
• Network Rigidity in GeSe2 Glass at High Pressure, S. Antao et al., Phys. Rev. Lett., 100, 115501 (2008); DOI: 10.1103/PhysRevLett.100.115501.
• Structure of glassy and liquid GeSe2, P. Salmon et al., J. Phys.: Condens. Matter, 15, S1509–S1528 (2003); DOI: 10.1088/0953-8984/15/16/301.