(1) Melting point : 9360C
(2) Atomic number : 32
(3) Energy gap : 0.6ev
(4) It is a gray metallic looking material.
(5) It is brittle and glass like in its mechanical properties.
(6) It crystallizes in the diamond cubic lattice.
(7) It has an intrinsic resistivity of 47 O-cm but may be doped with antimony or arsenic to give N-type resistivity of 0.01O-m or less and with boron, Gallium or Aluminium to give P-type resistivity of 0.001 O-m or less. It is usually prepared in high purity crystals from for electronics used by pulling from the melt either vertically or horizontally. To obtain intrinsic material, impurities of active elements must be in the range of 1part/billion or less. The active impurity such as Gallium, indium, arsenic, and antimony tend to diffuse rather slowly in germanium. The donors diffuse faster than the acceptors. It discovers use in close infrared detection and in X-ray detectors.