Germanium
A brittle, silvery-grey metalloid recovered mainly as a byproduct of zinc and coal processing. Critical for infrared optics, fibre optics and compound semiconductors used in ADAS, LiDAR and night-vision systems.
Overview
Germanium (symbol Ge, atomic number 32) is a hard, brittle metalloid with a diamond-cubic crystal structure and density of about 5.32 g/cm³. It is transparent to infrared wavelengths, which makes high-purity germanium the preferred material for IR lenses and windows in thermal imaging and night-vision cameras. In automotive programmes, germanium underpins ADAS sensing stacks: thermal night-vision modules, IR optics for blind-spot and pedestrian detection, and photodetector substrates for near-infrared LiDAR receivers. Silicon-germanium (SiGe) alloys also improve NIR sensitivity in CMOS image sensors and power high-speed electronics used in vehicle networks and radar front-ends. Supply is structurally tight: germanium is not mined as a primary ore but recovered from zinc smelter residues and some coal fly ash. China dominates refining and export volumes and has applied export licensing since August 2023, elevating germanium on EU and US critical raw material lists. For low-volume and premium OEMs specifying IR sensing packages, germanium is therefore both a performance enabler and a concentrated geopolitical risk in the bill of materials.
Automotive Applications
Similar Materials
Antimony
Metalloid
A lustrous, brittle grey metalloid primarily used as an alloying agent to harden lead and as a chemical synergist in flame retardants.
Tellurium
Metalloid
A brittle metalloid recovered almost entirely as a byproduct of copper electrolytic refining. Used in thermoelectrics, free-machining steels and specialty semiconductors relevant to automotive thermal management and electronics.
Beryllium
Alkaline Earth Metal
Elemental beryllium is a lightweight alkaline earth metal with exceptional stiffness-to-weight and thermal stability, used in aerospace structures, precision optics and specialised electronics. It is distinct from beryllium-copper (BeCu) alloys and carries significant toxicity and regulatory controls.
Indium
Post-transition Metal
A soft, silvery post-transition metal recovered mainly as a byproduct of zinc refining. Essential feedstock for indium tin oxide (ITO) transparent conductors, low-melting solders and compound semiconductors used in automotive displays, sensors and electronics.
Properties
Category
Type
Metalloid
Available Colors
Available Forms
Key Properties
- High IR transmittance (≈2–14 μm)
- High refractive index for compact optics
- Brittle metalloid; diamond-cubic structure
- Excellent semiconductor carrier mobility
- Recovered mainly as zinc/coal byproduct
- Geopolitically concentrated refining
Technical Specifications
Density
5.32 g/cm³
Tensile Strength
Not typically used as a structural metal (brittle metalloid)
Temperature Resistance
Melts at 938°C; IR optics typically rated for automotive under-hood/exterior sensor envelopes
Sustainability
Sustainability Rating
Primary supply depends on zinc smelting and coal byproducts, with high geographic concentration in China. Manufacturing scrap from IR lens machining is routinely recycled at relatively high rates, but end-of-life recovery from automotive and consumer electronics remains limited. Listed as a critical raw material in the EU and US due to supply risk.