Silicon Telluride Semiconductor Materials

Silicon telluride (Si₂Te₃) represents a class of layered chalcogenide semiconductors distinguished by a hexagonal arrangement of tellurium atoms interleaved with silicon dimers in octahedral sites. This unique crystal structure gives rise to strong in-plane covalent bonding and weaker van der Waals interactions between layers, enabling mechanical exfoliation down to few-layer or monolayer thickness. Si₂Te₃ exhibits a direct or near-direct band gap in the visible to near-infrared range, tunable with temperature, layer thickness and dimer orientation. High carrier mobilities, polarisation-dependent optical absorption and robust excitonic features render the material of great interest for optoelectronic and memory applications. Synthesis methods range from chemical vapour deposition to mechanical exfoliation and solution processing, affording control over crystal quality, lateral size and layer number. Demonstrated applications include photodetectors for telecommunication wavelengths, resistive-switching memory elements and on-chip optoelectronic integration. The compatibility of silicon telluride with existing silicon technology and its low-dimensional character underscore its potential to address global challenges in energy-efficient computing, optical communications and chemical sensing.

Research from Nature Portfolio

Recent studies have elucidated the anisotropic optical and vibrational properties of single-crystalline Si₂Te₃ nanoplates. Experimental measurements combined with first-principles calculations reveal that below 150 K the material adopts a direct band structure with a band-gap energy of approximately 2.39 eV and an exciton binding energy near 150 meV. Polarised reflection and Raman spectroscopy uncover a pronounced anisotropy in absorption coefficients and vibrational modes, directly linked to the orientation of silicon dimers within the tellurium lattice. These findings demonstrate how structural ordering governs optical response and suggest routes to engineer polarisation-sensitive photonic devices and high-resolution chemical sensors based on silicon telluride nanostructures.

Research from all publishers

Advances in resistive-switching behaviour of Si₂Te₃ nanowires have been reported, revealing reversible transitions between high- and low-resistance states under electrical bias. These transitions are attributed to potential-induced structural reconfiguration within the one-dimensional nanowire, yielding non-volatile memory performance with set and reset polarities determined by the initial bias. The stability of each state and the low switching energy highlight the promise of silicon telluride for emerging memory technologies.

Development of Si₂Te₃-based photodetectors for telecommunication wavelengths demonstrates its applicability in optical communications. Mechanically exfoliated multilayer flakes incorporated into back-gated phototransistors achieve hole mobilities around 0.36 cm² V⁻¹ s⁻¹ and responsivities exceeding 170 A W⁻¹ at 1310 nm. Frequency-response measurements indicate bandwidths up to several megahertz, while heterogeneous integration onto silicon waveguides yields functional on-chip detectors. These achievements underline the suitability of silicon telluride for broadband, low-dimensional optoelectronic integration.

Silicon Telluride Semiconductor Materials publication trend

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

Technical terms

Chalcogenide: A compound containing one or more chalcogen elements (oxygen group), here tellurium, bonded to a more electropositive element such as silicon.

Chemical vapour deposition (CVD): A synthesis technique in which volatile precursors react or decompose on a substrate to form a thin film or nanostructure.

Direct band gap: A semiconductor band structure in which the conduction-band minimum and valence-band maximum occur at the same momentum, enabling efficient light absorption and emission.

Exciton binding energy: The energy required to separate an electron–hole pair (exciton) into free charge carriers within a semiconductor.

Anisotropy: Directional dependence of a material property, such as optical absorption or electrical conductivity.

Resistive switching: The reversible change in electrical resistance of a material under applied voltage, enabling memory storage in memristive devices.

Photodetector: A device that converts incident photons into an electrical signal, characterised by responsivity and bandwidth.

References

1. Resistive switching in Si2Te3 nanowires. AIP Advances (2018).
2. Anisotropic optical properties of single Si2Te3 nanoplates. Scientific Reports (2020).
3. Si2Te3 Photodetectors for Optoelectronic Integration at Telecommunication Wavelengths. IEEE Journal of Selected Topics in Quantum Electronics (2021).