Topics Covered
Description
Applications
Chemical Properties
Electrical Properties
Thermal, Mechanical and Optical Properties
Safety Information
Description
Gallium phosphide (GaP) is a polycrystalline compound semiconductor that appears pale orange and has an indirect band gap of 2.26 eV. Single crystal wafers that are not doped have a clear orange color; however wafers that are doped strongly look darker as free-carrier absorption takes place. It does not dissolve in water and is odorless. The dopants used to obtain n-type semiconductors are tellurium or sulfur. For the p-type semiconductor, zinc is used.
Applications
Gallium phosphide is used in manufacturing low-cost red, orange, and green light-emitting diodes (LEDs) with low to medium brightness. Its life is relatively short at a higher current and it is sensitive to temperature during its lifetime. It can either be used alone or along with gallium arsenide phosphide.
Green light is emitted by pure gallium phosphide at a wavelength of 555 nm. GaP doped with nitrogen emits yellow-green light at a wavelength of 565 nm. GaP doped with zinc oxide emits red light at a wavelength of 700 nm. For red and yellow light, gallium phosphide is transparent, hence GaAsP-on-GaP LEDs are better than GaAsP-on-GaAs.
Chemical Properties
The chemical properties of Gallium Phosphide are provided in the table below:
|
Chemical Properties |
|
Chemical Formula |
GaP |
|
Molecular Weight |
100.697 |
|
CAS No. |
12063-98-8 |
|
IUPAC Name |
Gallanylidynephosphane |
|
Group |
III-V |
|
Band Gap |
2.26 eV |
|
Band Gap Type |
Indirect |
|
Crystal Structure |
Zinc Blende |
|
Symmetry Group |
Td2-F43m |
|
Lattice Constant |
5.4505 Å |
Electrical Properties
The electrical properties of Gallium Phosphide are provided in the table below:
|
Electrical Properties |
|
Intrinsic Carrier Concentration |
2.7 x 106 cm-3 |
|
Electron Mobility |
≤ 250 cm2 V-1 s-1 |
|
Hole Mobility |
≤ 150 cm2 V-1 s-1 |
|
Electron Diffusion Coefficient |
≤ 6.5 cm2 s-1 |
|
Hole Diffusion Coefficient |
≤ 4 cm2 s-1 |
Thermal, Mechanical and Optical Properties
The thermal, mechanical and optical properties of Gallium Phosphide are provided in the tables below:
|
Mechanical Properties |
|
Melting Point |
1477 °C |
|
Density |
4.138 g cm-3 |
|
Young's Modulus |
8.8 x 1011 |
|
Thermal Properties |
|
Thermal Conductivity |
1.1 W cm-1 °C-1 |
|
Thermal Diffusivity |
0.62 cm2 s-1 |
|
Thermal Expansion Coefficient |
4.65x10-6 °C-1 |
|
Optical Properties |
|
Refractive Index (589 nm @ 293 K) |
3,02 |
|
Radiative Recombination Coefficient (@ 300 K) |
10-13 cm3 s-1 |
Safety Information
|
Safety Information |
|
GHS Hazard Statements |
H319- Cause serious eye irritation
H335- Cause respiratory irritation |
|
Safety Precautions |
S 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice |
Source: AZoM