Copper doped germanium

Bode and Graham (1963) A Comparison of the Performance of Copper-Doped Germanium and Mercury-Doped Germanium Detectors by D. Bode and H. A. Graham, Infrared Phys. 3, 129-137. 

Very recently, Bailey and Richards (23) have shown that a high degree of sensitivity for adsorbed species can be achieved by measuring the absorption of infrared radiation on a thin sample cooled to liquid helium temperature. The optical arrangement used in these studies is shown in Figure 10. The modulated beam produced by the interferometer is introduced into the UHV sample chamber and reflected off a thin slice of monocrystalline alumina covered on one side by a 1000 k film of nickel or copper. Radiation absorbed by the sample is detected by a doped germanium resistance thermometer. The minimum absorbed power detected by this device when operated at liquid helium temperature is 5 x 10 14 W for a 1 Hz band width. With this sensitivity absorbtivities of 10"4 could be measured. 

Sb-doped germanium samples diffused with copper show absorption thresholds at 0.32 eV in the near IR which can be associated with the onset of the... 

Photon detectors consist of a thin film of semiconductor material, such as lead sulfide, lead telluride, indium antimonide, or germanium doped with copper or mercury, deposited on a nonconducting glass and sealed into an evacuated envelope. Photon flux impinging on the semiconductor increases its conductivity. Lead-sulfide detectors are sensitive to radiation below about 3 fj.m in wavelength and have a response time of about 10 /nsec. Doped germanium detectors cooled to liquid-helium temperatures are sensitive to radiation up to about 120 jitm in wavelength, and have a response time of approximately 1 nsec. 

Uses. In metallurgy for hardening copper and lead alloys to prepare GaAs for electronic devices, doping agent in germanium and silicon solid state products, special solders. 

FERMI SURFACE OF GERMANIUM It is doped with Arsenic to make it an n-type semi-conductor. The Fermi surface differs markedly from that of copper, showing far fewer electrons available for conduction Yet, the Brillouin zone is the same as that for... 

In the far-IR, where photon energies are very low, quantum detectors cannot be used at all. Two types of thermal detectors, each operating at liquid-helium temperatures, have been used. The first one is the germanium bolometer, often doped with a low level of copper, gallium or antimony. For increased responsivity, these detectors are cooled down to 1.5 K by pumping the detector cryostat. The second type is the InSb hot-electron detector. 

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