Two-Dimensional Germanium and Silicon Nanomaterials

Two-dimensional (2D) forms of group-14 elements, notably germanium and silicon, have emerged as versatile platforms for next-generation electronics, energy storage and sensing. In contrast to their bulk counterparts, monolayer and few-layer architectures such as germanene and silicene feature a low-buckled honeycomb lattice that confers Dirac-type electronic dispersion, high carrier mobility and tuneable bandgaps. Hydrogen-terminated derivatives, germanane and silicane, exhibit enhanced ambient stability and adjustable optical and electronic properties through surface chemistry. Alloyed 2D sheets, such as siligene, combine the attributes of silicon and germanium, offering synergistic effects in conductivity and mechanical resilience. Synthetic routes encompass topotactic deintercalation of Zintl phases, electrochemical exfoliation and in situ chemical functionalisation, each tailored to improve flake quality and yield. Challenges remain in controlling oxidation, delamination and uniformity at scale. Nevertheless, recent advances in strain engineering, surface chemistry and device integration have accelerated applications in field-effect transistors, photodetectors, flexible electronics, lithium-ion battery anodes and chemical- and biosensing, underscoring the global impact of these elemental nanomaterials.

Research from Nature Portfolio

Investigations into methylated germanium single layers have revealed that GeCH₃ monolayers can be driven into a paramagnetic state under external magnetic fields, while electron doping and biaxial tensile strain markedly enhance thermoelectric performance. Tight-binding and Green’s function analyses demonstrate increased electronic heat capacity, electrical conductivity and Seebeck coefficient with field and doping, whereas compressive strain suppresses these properties. The combined tunability of magnetic susceptibility and thermal transport suggests promising avenues for spintronic, valleytronic and thermoelectric devices based on functionalised 2D germanium.

Two-Dimensional Germanium and Silicon Nanomaterials publication trend

The graph below shows the total number of articles in two-dimensional germanium and silicon nanomaterials across all publications each year (not limited to Nature Index journals).

Technical terms

Germanene: A single layer of germanium atoms in a buckled honeycomb lattice, exhibiting Dirac electronic dispersion and high carrier mobility.

Silicene: A two-dimensional form of silicon with a low-buckled hexagonal arrangement, analogous to graphene but prone to oxidation.

Germanane/Silicane: Hydrogen-terminated monolayers of germanene and silicene, respectively, offering enhanced air stability and tuneable bandgaps.

Siligene: A 2D alloy composed of silicon and germanium in a single low-buckled lattice, combining properties of both elements.

Topotactic Deintercalation: A chemical process removing interlayer atoms from a layered precursor to yield hydrogen-terminated 2D materials.

Biaxial Strain: Uniform mechanical deformation applied along two in-plane axes to modulate electronic and thermoelectric properties.

References

1. Multi‐Sensing Platform Based on 2D Monoelement Germanane. Advanced Materials (2023).
2. Electrochemical Decalcification–Exfoliation of Two-Dimensional Siligene, Si x Ge y : Material Characterization and Perspectives for Lithium-Ion Storage. ACS Nano (2023).
3. Faster and Safer “In situ” Synthesis of Germanane and Silicane. Small Methods (2024).
4. Investigating the magnetic, thermoelectric, and thermodynamic properties of the GeCH3 single-layer considering external magnetic field, doping, and strain. Scientific Reports (2023).
5. Germanium‐based monoelemental and binary two‐dimensional materials: Theoretical and experimental investigations and promising applications. InfoMat (2022).
6. Design, characterization, and application of elemental 2D materials for electrochemical energy storage, sensing, and catalysis. Materials Advances (2020).