Semiconductor materials

semiconductor-materials

10 materials across 5 types

About semiconductor materials

Semiconductor materials (silicon, germanium, silicon-germanium, gallium arsenide, gallium nitride, selenium, tellurium, bismuth telluride): band gap, thermal and electrical data with sources.

Semiconductors are the base of chips, solar cells, detectors and thermoelectric generators. Their electrical behaviour depends strongly on purity, doping and temperature, so each value names its condition.

At a glance

Highest density: Bismuth telluride reaches 7.64 g/cm³. Lowest: Silicon starts at 2.33 g/cm³. (10 of 10 grades have a sourced value.)
Highest melting point: Gallium nitride (GaN) reaches 2,500 °C. Lowest: Selenium starts at 221 °C. (9 of 10 grades have a sourced value.)

Ranges run across the conditions each source reports (temper, heat treatment, form), measured at room temperature where the source says so.

How they compare

The same measurements for every material in the collection. A range means the grade has values under several conditions; "at least" means the source gives a specified minimum. "no data" means no sourced value yet. For ranked tables, open a benchmark.

Semiconductor materials: how the grades compare
Material	Density	Melting point	Electrical resistivity	Thermal conductivity	Young's modulus	Thermal expansion
Siliconsemiconductor	2.33 g/cm³	1,415 °C	no data	150 W/(m·K)	no data	no data
Germaniumsemiconductor	5.33 g/cm³	936 to 937 °C	no data	58.6 W/(m·K)	103 GPa	5.8 to 6.1 ppm/K
Silicon-germanium alloy (SiGe)semiconductor	4.31 g/cm³	no data	no data	no data	no data	no data
Gallium arsenide (GaAs)semiconductor	5.32 g/cm³	1,238 to 1,240 °C	3,300,000 Ω·m	46 to 55 W/(m·K)	no data	5.73 to 6.86 ppm/K
Gallium nitride (GaN)wide-bandgap semiconductor	6.15 g/cm³	2,500 °C	no data	130 W/(m·K)	no data	5.59 ppm/K
Arsenic (As)Metalloid: feedstock for gallium arsenide semiconductors and a dopant	5.73 g/cm³	817 °C	no data	50 W/(m·K)	8 GPa	no data
Boronneutron absorber, hard amorphous powder and reinforcing fibre	2.35 to 2.61 g/cm³	2,075 °C	no data	27 W/(m·K)	428 GPa	4.5 to 6 ppm/K
Seleniumchalcogen element; photoconductor and CIGS solar-cell component	4.81 g/cm³	221 °C	no data	0.52 W/(m·K)	10 GPa	no data
Telluriummetalloid, semiconductor compound element and alloy additive	6 to 6.25 g/cm³	450 °C	no data	3 W/(m·K)	43 GPa	no data
Bismuth telluridethermoelectric alloy base and layered topological insulator	6.5 to 7.64 g/cm³	573 to 629 °C	no data	1.29 to 1.48 W/(m·K)	no data	no data

What these materials are made of

Composition by weight, as printed in the sources for each grade (the first constituents listed).

Composition of each grade
Material	Main constituents
Silicon	Si 100%
Germanium	Ge 100%
Silicon-germanium alloy (SiGe)	Si 80% · Ge 20%
Gallium arsenide (GaAs)	Ga 48.2% · As 51.8%
Arsenic (As)	As 100.0%
Boron	10B 20% · 11B 80%
Selenium	Se 100%
Tellurium	Te 100.0%
Bismuth telluride	Bi 40% · Te 60%

Where they are used

Uses
Use	Grades
Single-crystal silicon wafer substrate	Silicon
Semiconductor chips	Silicon
Silicon solar cell	Silicon
Infrared lenses and windows for thermal imaging	Germanium
ATR prisms for infrared spectroscopy	Germanium
Optical fibre glass	Germanium
SiGe heterojunction bipolar transistors (HBTs) in RF and mixed-signal chips	Silicon-germanium alloy (SiGe)
SiGe strain layer in CMOS transistors	Silicon-germanium alloy (SiGe)
Radioisotope thermoelectric generators (MHW-RTG and GPHS-RTG; a power source, not a battery)	Silicon-germanium alloy (SiGe)
Triple-junction space solar cell (GaInP/GaAs/Ge)	Gallium arsenide (GaAs)
Power amplifier in cellular handsets	Gallium arsenide (GaAs)
Laser diodes, LEDs and photodetectors	Gallium arsenide (GaAs)
GaN power transistor (EPC2045, 100 V)	Gallium nitride (GaN)
GaN integrated circuits and optoelectronic devices	Gallium nitride (GaN)
EPC1001 enhancement-mode GaN transistor (ground test)	Gallium nitride (GaN)
Gallium arsenide and indium gallium arsenide semiconductors	Arsenic (As)

When each grade fits

Best use and weak spots of each grade
Material	Best for	Weakest at
Silicon	Semiconductor wafers: a 1.12 eV band gap at 300 K and a well-documented resistivity range from doping	Light emission and heat flow: an indirect band gap (not stated in the sources read) and thermal conductivity of 150 W/(m·K), well below metals
Germanium	Infrared optics from 1.8 to 23 µm (thermal-imaging lenses, ATR prisms) and substrates for triple-junction space solar cells	Temperature limit and supply: Crystran says germanium becomes opaque at all wavelengths a little above 350 K, and the USGS says supply runs through a few producers, China the leading one
Silicon-germanium alloy (SiGe)	High-temperature thermoelectric legs for radioisotope generators, and SiGe transistors for fast RF chips	Thermoelectric efficiency: NASA says the figure of merit of Si-Ge is much lower than that of lead telluride
Gallium arsenide (GaAs)	Light emission, RF power and multijunction space solar cells, where the band gap and electron mobility of GaAs beat silicon (1.424 eV and up to 8500 cm2/(V·s))	Cost and toxicity: the arsenic content is classed as carcinogenic in GHS, and the gallium supply is concentrated in China (99% of primary low-purity gallium)
Gallium nitride (GaN)	High-voltage and high-frequency power switching, and radiation-tolerant electronics where a wide band gap and high breakdown field matter (NASA ground tests of GaN transistors)	Modest electron mobility compared with the best III-V materials, and the cost and limited supply of gallium
Arsenic (As)	Source of high-purity arsenic metal for GaAs and InGaAs semiconductors and for specialty infrared optics (USGS)	Toxicity: PubChem reports H301 and H331 for most reporting companies, and ATSDR classes inorganic arsenic as a known human carcinogen
Boron	Thermal-neutron absorption where boron-10 content matters (NIST cross sections; NASA 1995 shielding report) and boron fibre for stiff composite plies (Specialty Materials datasheet)	Oxidation and reactivity: amorphous boron powder can ignite spontaneously as dust and reacts violently with steam at red heat (Materion; PubChem, citing Bretherick)
Selenium	Thin-film photovoltaics and photoconductive devices where a selenium compound is the active absorber or photoconductor	Toxicity and reactivity: the supplier SDS classes it as toxic if swallowed or inhaled, it burns in air when heated, and it releases toxic hydrogen selenide if heated above 50 degC in water
Tellurium	CdTe thin-film solar cells and bismuth telluride thermoelectric devices, the two largest uses (USGS)	Supply and toxicity: most of it is a copper by-product, China leads refined output, and the element is toxic if swallowed
Bismuth telluride	Room-temperature thermoelectric coolers and generators, where the p-type alloy reached zT 1.24 before storage	Humid, hot storage: 600 h at 85 degC and 85% RH oxidised the surface and cut zT by 19 and 22 percent (authors)