Germanene, stanene and plumbene

Ge, Sn, Pb

Also called heavier group-14 Xenes, germanane (hydrogenated germanene)

exists only on a substrate depends on form

The heavier cousins of silicene. Heavier atoms bring stronger spin–orbit coupling, which could make these sheets conduct only along their edges and without resistance – a quantum spin Hall insulator. That promise drives the research; in practice all of them must be grown atom by atom on specific crystal surfaces and interact strongly with them.

Cell: Hexagonal, a = 3.97 Å
Atoms per cell: 2
Ge–Ge bond: 2.38 Å
Height: 0.64 Å between the outer atom centres

The low-buckled honeycomb of silicene, with more buckling: 0.64 Å. Going down the group from silicon to tin and lead, the atoms get heavier, the buckling grows and spin–orbit coupling strengthens, which is why stanene is a candidate quantum spin Hall insulator with a gap of order 0.1 eV. Stanene and plumbene are predicted to take the same buckled form. DFT (LDA) prediction for the free-standing sheet: a = 3.97 Å, buckling 0.64 Å.

Data sheet

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Kind of sheet: exists only on a substrate
Only stable on the surface it was grown on
Behaves as: depends on form
Band gap: Predicted spin–orbit gaps grow with atomic mass: ~24 meV for germanene and ~0.1 eV for stanene (free-standing), up to ~0.3 eV for functionalised stanene. Germanane (GeH) is a direct-gap semiconductor of ~1.5 eV
Thickness: One buckled atomic layer
Structure: Buckled honeycomb lattices, with buckling increasing down the group; stanene can adopt low-buckled or ultraflat forms on some substrates. All known forms are substrate-supported, except chemically terminated versions such as germanane
Stability: The bare layers oxidise quickly in air. Hydrogen- or methyl-terminated germanane is considerably more robust.
First made: Germanane (GeH) in 2013 (Bianco and colleagues); germanene on Au(111) in 2014 (Dávila and colleagues); stanene on Bi₂Te₃ in 2015 (Zhu and colleagues)

Compare with other materials

Key properties

Predicted spin–orbit gap ~24 meV for germanene and ~0.1 eV for stanene (free-standing, DFT)
Stanene first grown on Bi₂Te₃(111) in 2015; an ultraflat stanene with band inversion reported on Cu(111)
Germanane, made by removing calcium from CaGe₂, is a direct-gap semiconductor of ~1.5 eV and far more air-stable than germanene
Plumbene, the lead member, was first reported by epitaxial growth in 2019

How it is made

MBE on metal or topological-insulator substrates – Au(111), Al(111), Cu(111), Bi₂Te₃, InSb(111)
Topotactic deintercalation of Zintl phases such as CaGe₂ to form hydrogen- or methyl-terminated layers
Segregation growth, in which germanium reaches the surface through a thin metal film

Uses, and how close they are

Quantum spin Hall edge-state deviceslab
Germanane as a direct-gap semiconductor for optoelectronicslab

Readiness runs lab → prototype → pilot → deployed.

Open problems

Can a heavy Xene be grown on a substrate weak enough to preserve its predicted topological gap – and can helical edge conduction be shown in transport?
How much of the measured electronic structure reflects surface alloying rather than a genuine Xene?
Can functionalised versions such as fluorinated stanene deliver quantum spin Hall behaviour at room temperature?

Going deeper

Short notes for specialists. Choose a lens in the header and yours comes first.

For theoreticians · your lens

A natural home for Kane–Mele physics with large spin–orbit coupling. Include SOC self-consistently and model the substrate explicitly, because strain and hybridisation can close or invert the gap. Hybrid functionals and GW shift band inversions; compute Z₂ invariants (for example via Wannier charge centres) for the supported geometry, not only the free-standing one.

For experimentalists · your lens

In-situ STM/STS, LEED and ARPES are essential. Edge-state claims from STS need spatially resolved spectra along clean edges. Distinguish buckled Xene reconstructions from surface alloys by combining STM with core-level spectroscopy and simulated images.

For engineers · your lens

Not manufacturable: vacuum epitaxy on specialised single-crystal substrates and poor air stability. Germanane, made by wet chemistry from Zintl phases, is the only family member with a plausible processing route.

In the research tracks

Theory frontiers

Topological phases in 2D crystals

Recent news

The newest items tagged Germanene, stanene, from the news feed updated 5 Oct 2026.

Preprintnot yet peer reviewed 8 Sep 2026 arXiv

Decorated electronic kagome lattice in twisted bilayer germanene

Artificial kagome lattices provide a route to electronic flat bands, geometric frustration, and correlation driven phases, but their realization in atomically controlled two-dimensional materials remains scarce. Here, we show that commensurate twisted bilayer germanene on Ge2Pt produces two electronically distinct…

TheoryExperimentGermanene, stanene

Preprintnot yet peer reviewed 4 Sep 2026 arXiv

First principles calculations of electric-field-driven topological phase transitions in silicene, germanene and stanene

The emergence of two-dimensional topological materials, particularly the group-14 monolayers known as silicene, germanene, and stanene has opened promising pathways for next-generation nanoelectronics and spintronics. Their buckled honeycomb structure and strong spin-orbit coupling allow for bandgap engineering via a…

TheoryGermanene, stanene Silicene

Preprintnot yet peer reviewed 25 Aug 2026 arXiv

Intervalley Magnetotrions Tunable by Electric and Magnetic Fields in Buckled Two-Dimensional Materials

We develop a theoretical framework for intervalley magnetotrions in buckled two-dimensional materials, including silicene, germanene, and stanene, subjected to perpendicular electric and magnetic fields. Within the effective-mass approximation, the three-particle Schrödinger equation is formulated with the…

TheoryGermanene, stanene Silicene

Preprintnot yet peer reviewed 17 Mar 2026 arXiv

Low bending rigidity and large Young's modulus drive strong flexural phonon renormalization in two-dimensional monolayers

Many intriguing phenomena such as the wave-like hydrodynamic heat flow, the logarithmic divergence of electrical resistivity at low temperatures and microscale kirigami are driven by flexural acoustic (ZA) phonons in two-dimensional (2D) materials. Yet, a definitive first-principles description of their dispersion…

TheoryGermanene, stanene Graphene MoS₂

Preprintnot yet peer reviewed 11 Mar 2026 arXiv

Electron-phonon physics at the exascale: A hybrid MPI-GPU-OpenMP framework for scalable Wannier interpolation

We demonstrate a highly efficient GPU implementation of the Wannier interpolation of electron-phonon matrix elements in the EPW code. Building on a systematic analysis of the computational complexity of the algorithm for electron-phonon interpolation, we designed a GPU porting strategy that integrates naturally into…

TheoryGermanene, stanene MoS₂

All 5 items tagged Germanene, stanene in the news feed · RSS feed for Germanene, stanene

Key references

Stability and exfoliation of germanane: a germanium graphane analogueBianco et al. · ACS Nano 7, 4414 (2013)cited by 1,105doi:10.1021/nn4009406
Germanene: a novel two-dimensional germanium allotrope akin to graphene and siliceneDávila et al. · New Journal of Physics 16, 095002 (2014)cited by 1,610doi:10.1088/1367-2630/16/9/095002
Epitaxial growth of two-dimensional staneneZhu et al. · Nature Materials 14, 1020 (2015)cited by 1,799doi:10.1038/nmat4384
Large-gap quantum spin Hall insulators in tin filmsXu et al. · Physical Review Letters 111, 136804 (2013)cited by 1,330doi:10.1103/PhysRevLett.111.136804