Germanium

Giredmet JSC has developed and commercialized technologies for:

  • the production of high-purity germanium tetrachloride used to obtain germanium dioxide;
  • the production of polycrystalline zone-refined crystals used to grow single crystals of germanium;
  • the production of single crystals used for infrared optics;
  • the production of high-purity single crystals of germanium used for gamma radiation detectors.

 

Quality indicators (measurements) Monocrystals for solar cells (Sc-solar Cell) Monocrystals and polycrystals for infrared optics devices
 Special-purpose monocrystals
Orientation

(111),(100), (100+6→111), (100+9→111)

 (111) (111), (110), (100)
Type of conductivity n, p n n, p
Doping agent Sb, Ga Sb Sb, Ga
Resistivity ohm·cm by agreement 5-40 (or by agreement) 0,01-45
Dislocation density (Nd), cm-2 less than 5000 less than 5000 less than 200
Diameter, mm up to 105 7,5-105 20-35
Length, mm minimum 60 minimum 50 minimum 40
Special requirements by agreement optical characteristics – on request dislocation density, resistivity, lifetime and other characteristics – by agreement

 

Monocrystals and polycrystals of germanium grown by the Czochralski method are used for infrared optical products:

 

Refractive index n at 200Ń and λ=10 µm 4/0032 ± 0/0002
The homogeneity of the refractive index Δn ≤2·10-4
The temperature coefficient of the refractive index dn/dT at (20 25)0Ń, C-1; ≤4·10-4
The absorption coefficient αλ (attenuation index) with λ=10,6 µm, cm-1 less than 0,03