Elemental Semiconductors

Elemental semiconductors comprise single chemical elements whose electronic band structure exhibits an intrinsic band gap sufficiently small to allow thermal or optical excitation of charge carriers. Silicon and germanium dominate both research and industry due to their mature crystal growth, stable oxide formation and moderate band gaps of approximately 1.1 eV and 0.66 eV respectively. Carbon in the diamond structure also displays a wide gap near 5.5 eV, while emerging interest in two-dimensional allotropes such as silicene and germanene promises novel physics at reduced dimensionality. Controlled addition of donors or acceptors transforms intrinsic materials into n- or p-type, enabling rectifying junctions and field-effect devices at the heart of modern microelectronics. Ongoing advances aim to enhance carrier mobility, extend operating temperatures and integrate elemental semiconductors with other material platforms. Applications span logic and memory circuits, photodetectors, solar cells and emerging quantum technologies, underscoring the global impact of elemental crystalline semiconductors in both established and nascent sectors.

Research from Nature Portfolio

Recent studies have pioneered electrically programmable transistor architectures on elemental semiconductor substrates. One work reported a silicon-on-insulator device whose single back-bias voltage selects p-type, n-type or ambipolar conduction, enabling three analogue functions—phase shifting, frequency doubling and voltage following—within a single transistor footprint. Temperature-dependent measurements and simulations have elucidated the transport physics underpinning these modes. In parallel, a nonvolatile reconfigurable field-effect transistor has been demonstrated by introducing floating charge storage layers at the source and drain in a silicon heterostructure. This design achieves polarity control with a single control gate, boosting on-state currents while suppressing leakage without the need for multiple programme voltages.

Research from all publishers

In-depth analysis of metal-semiconductor contacts has revealed that single-crystalline aluminium contacts to silicon and germanium nanowires exhibit symmetric Schottky barriers for electrons and holes in the Al–Si system, and highly transparent hole injection in Al–Ge, guiding optimal contact engineering for elemental semiconductors. Elsewhere, germanium-based reconfigurable transistors monolithically integrated on silicon-on-insulator platforms have achieved symmetric on-currents and dynamic polarity control using multi-gate architectures, demonstrating basic logic operations within a single device. Further work on composition-tunable Si₁₋ₓGeₓ nanosheets with void-free aluminium junctions has shown abrupt interfaces and ultra-thin silicon interlayers that stabilise transport, offering a versatile route to scalable elemental semiconductor devices.

Elemental Semiconductors publication trend

The graph below shows the total number of articles in elemental semiconductors across all publications each year (not limited to Nature Index journals).

Technical terms

Elemental semiconductor: A pure chemical element whose crystalline form has an electronic band gap allowing controlled charge excitation.

Band gap: Energy difference between the valence band maximum and conduction band minimum, governing intrinsic carrier generation.

Schottky barrier: Energy barrier at a metal-semiconductor interface that controls charge-carrier injection.

Ambipolar conduction: Charge transport regime where both electrons and holes contribute significantly under specific bias.

Doping: Intentional introduction of impurity atoms to control the concentration and type of mobile charge carriers.

References

1. Three-to-one analog signal modulation with a single back-bias-controlled reconfigurable transistor. Nature Communications (2022).
2. Understanding the Electronic Transport of Al–Si and Al–Ge Nanojunctions by Exploiting Temperature-Dependent Bias Spectroscopy. ACS Applied Materials & Interfaces (2024).
3. A Run-Time Reconfigurable Ge Field-Effect Transistor With Symmetric On-States. IEEE Journal of the Electron Devices Society (2024).
4. Composition Dependent Electrical Transport in Si1−xGex Nanosheets with Monolithic Single‐Elementary Al Contacts. Small (2022).
5. A dual doping nonvolatile reconfigurable FET. Scientific Reports (2023).