Silicon
Element 14 · chemical symbol: Si
These Vrulum profiles mention Silicon by name. Read each profile for its specific context; a mention alone does not establish composition, performance or use of the pure element.
For periodic-table data and other properties, consult the Royal Society of Chemistry periodic table.
Related technology profiles
2D semiconductor electronics
Two-dimensional semiconductors such as molybdenum disulfide (MoS2) form sheets only a few atoms thick and could make transistors that keep working at very small sizes. Lab devices and a small 1-bit processor have been demonstrated, but no production chips built from these materials are described in the sources reviewed here.
Aerogels
Aerogels are extremely porous, very low-density solids made by removing the liquid from a gel while keeping its solid network intact. Silica aerogels are already used as high-performance thermal insulation and in space missions, but they are brittle and need careful drying to make.
AI-assisted chip design
AI-assisted chip design uses machine learning to place large circuit blocks on a chip and to tune the settings of design software. Google's AlphaChip and commercial tools from Synopsys and Cadence report large gains, but Google's central performance claims are disputed and the company figures have not been independently verified.
Artificial photosynthesis
Artificial leaves are devices that use sunlight to split water into hydrogen and oxygen in one integrated unit. Laboratory modules have reached about 11% solar-to-hydrogen efficiency under one-sun illumination, but durability and outdoor performance at useful scale have not yet been shown.
Battery-free wireless implant sensors
Researchers have built flexible wireless sensors that can detect water getting through the protective coating of an implant, without an onboard battery. The tests so far are laboratory, explanted tissue and post-mortem experiments, not monitoring in living patients.
Bioresorbable (transient) electronics
Bioresorbable electronics are working circuits, sensors and stimulators made from materials designed to dissolve in the body after a set time. They aim to provide temporary implants, such as short-term pacemakers or brain pressure monitors, that never need surgical removal.
Chiplets and advanced chip packaging
Chiplet designs build a processor from several smaller silicon dies joined by advanced packaging, which can make large designs easier to manufacture and reuse. The joins add cost, heat and capacity limits, and standards such as UCIe and packaging routes from TSMC and Intel are moving the approach into commercial products.
Event-based (neuromorphic) cameras
Event-based cameras have pixels that report only when the brightness at that pixel changes, instead of recording full frames at a fixed rate. This gives very fast response, a wide range of brightness that a camera can handle, and low data output, and it needs new software to use well.
Extreme ultraviolet (EUV) lithography
Extreme ultraviolet (EUV) lithography prints the finest features on the most advanced chips, using 13.5 nm light made from tin plasma and optics built by ASML, which is the only maker of these machines. Intel reports that High-NA systems are in high-volume manufacturing for a subset of processors at one chipmaker, but cost, source power and a single supplier remain the main limits.
High-density neural probes
High-density neural probes are thin silicon shanks with hundreds or thousands of recording sites, such as Neuropixels, that record many individual neurons at once. In mice and rats they have followed the same neurons for more than two months, while in people they have so far been used mainly during brain surgery, where recording yield and probe durability remain limits.
Industrial steelmaking
Industrial steelmaking turns molten iron into steel by removing carbon and other impurities. The main methods date from the Bessemer process of 1856 and the open-hearth furnace, and today's routes are the basic oxygen furnace and the electric arc furnace.
Neuromorphic computing chips
Neuromorphic chips are processors designed around ideas from the brain, such as many simple neurons that communicate with short spikes and memory placed right next to computation. Research chips and large research systems exist and report large energy savings on some tasks under specific test conditions, but they are not yet a mainstream alternative to GPUs.
Optical interconnects and co-packaged optics
Optical interconnects carry data between chips, switches and racks as light rather than electrical current. Co-packaged optics (CPO) places the optical engines inside the same package as the switch or processor, which shortens the electrical links and may reduce power per bit, but the approach is still in early industrial use.
Passive daytime radiative cooling
Passive daytime radiative cooling uses surfaces that reflect almost all sunlight while giving off heat as infrared light that escapes through the atmosphere into space. Laboratory and rooftop tests have cooled surfaces several degrees below the surrounding air in full sun without using electricity.
Perovskite-silicon tandem solar cells
Perovskite-silicon tandem solar cells stack a thin perovskite layer on top of a conventional silicon cell so that each layer captures a different part of sunlight. Certified laboratory cells have passed the efficiency limit of single-junction silicon, a certified 60 cm² device reached 28.9% in 2025, and first commercial modules shipped in 2024, but long-term outdoor durability is still being proven.
Photonic computing for AI
Photonic computing uses light, rather than electrical signals, to carry out some of the matrix calculations used in AI. Laboratory chips have run small neural networks and a packaged optical accelerator, but the sources reviewed here do not show that photonic chips outperform electronic hardware on real AI workloads.
Photonic integrated circuits
Photonic integrated circuits put lasers, waveguides, modulators and detectors on a single chip so that light, rather than only electricity, carries and processes signals. Silicon photonics has established foundry access, and Broadcom's 2025 co-packaged optics switch uses silicon photonics engines. Thin-film lithium niobate and indium phosphide serve other functions.
Quantum repeaters and quantum networks
Quantum repeaters use quantum memories to store entanglement while it is passed along a chain of links, so that entanglement can reach beyond the distance that a single optical fibre allows. Small laboratory networks with two or three nodes, some linked over deployed fibre, have now been reported, but the sources reviewed here show no repeater chain yet working over long distances.
Silicon spin qubits
Silicon spin qubits store quantum information in the spin of a single electron held in a tiny silicon structure. Recent results show two-qubit devices made in a 300 mm semiconductor foundry reaching gate fidelities above 99%, but these are small arrays and the field has not yet shown error-corrected logical qubits.
Solid-state lidar
Solid-state lidar measures distance with laser light using few or no large moving parts. It uses flash illumination, optical phased arrays or chip-scale FMCW. Chip results have been shown in the laboratory, but independent evidence of long-range, low-cost sensors in production is still limited.