Germanium arsenides

Sudden change in the composition of As 3d peak is observed at the same temperature of 500°C there apvpears another arsenic compound with germanium. The peak fitting component designated as C2, is shifted by 0.8 eV in relation to the bulk component B (Fig. 17). The similar state of arsenic is described in (Studd et al., 1983) for germanium arsenide... 

The supplanting of germanium-based semiconductor devices by shicon devices has almost eliminated the use of indium in the related ahoy junction (see Semiconductors). Indium, however, is finding increased use in III—V compound semiconductors such as indium phosphide [22398-80-7] for laser diodes used in fiber optic communication systems (see Electronic materials Fiber optics Light generation). Other important indium-containing semiconductors include indium arsenide [1303-11-3] indium antimonide [1312-41 -0] and copper—indium—diselenide [12018-95-0]. 

Eig. 3. Electron (—) and hole (-) velocities versus electric field for high purity siUcon, Si germanium, Ge and gallium arsenide, GaAs, at 300 K (26). 

Germanium (pure), galium arsenide Germanium (doped, transistor-grade)... 

Consider the number of valence electrons in each element. clO-0096. Draw a band-gap diagram for gallium arsenide doped with zinc. clO-0097. Draw a band-gap diagram for germanium doped with phosphorus. 

Figure 3.15 shows the spectral dependence of the specific detectivity, D, reported for germanium and indium arsenide photodiodes, respectively. The main properties of these detectors are also summarized in Table 3.1 for comparison. 

Figure 3.15 The specific sensitivities reported for germanium and indium arsenide photodiodes.

Arsenides of gallium and germanium have not been prepared. 

ELECTROLUMINESCENCE. Luminescence generated in crystals by electric fields or currents in the absence of bombardment or other means of excitation. It is a solid-state phenomenon involving />- and n-type semiconductors, and is observed in many crystalline substances, especially silicon carbide, zinc sulfide, and gallium arsenide, as well as in silicon, germanium, and diamond. 

Semiconductor A generic term for a device that controls electrical signals. It specifically refers to a material (such as silicon, germanium or gallium arsenide) that can be altered either to conduct electrical current or to block its passage. Carbon nanotubes may eventually be used as semiconductors. Semiconductors are partly responsible for the miniaturization of modem electronic devices, as they are vital components in computer memory and processor chips. The manufacture of semiconductors is carried out by small firms, and by industry giants such as Intel and Advanced Micro Devices. 

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