Gallium arsenide, GaAs

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

Arsenic (As), 3 262-274. See also GaAsP system Gallium arsenide (GaAs) semiconductor InGaAsP entries Indium-gallium-arsenside (InGaAs) photodiodes... 

See also Gallium arsenide (GaAs) semiconductor GaAsP system... 

Gallium arsenide (GaAs), 3 270-271 carrier mobility at room temperature, 5 597t... 

Recently, polyethylene and Teflon mesh sample holders have been used. A drop of sample is placed on the mesh and spread to a relatively uniform thickness for analysis. These holders can often be rinsed and reused. A very convenient alternative to liquid sample holders is the technique called attenuated total reflection or ATR. The ATR cell is a crystal of gallium arsenide, GaAs and the infrared radiation enters one end of the trapezoidal crystal. With the angles adjusted to obtain total internal reflection, all of the IR radiation passes through the crystal and exits the other end as shown in Fig. 5.14. 

Silicon is the most popular material for photovoltaic (PV) power. Another material is gallium arsenide (GaAs), which is a compound semiconductor. GaAs has a crystal structure similar to that of silicon, but it consists of alternating gallium and arsenic atoms. It is well suited for PV applications since it has a high light absorption coefficient and only a thin layer of material is required, which reduces the cost. 

Other linear focused photomultipliers reported in near-IR fluorescence studies include the Hamamatsu R943-02 52 and the RCA C31034 85 86) both incorporating gallium-arsenide (GaAs) photocathodes. 

Various inorganic semiconductors (p-type and/or n-type nonoxide semiconducting materials) sucb as amorphous or crystalline silicon (a-Si or c-Si), gallium arsenide (GaAs), cadmium telluride (CdTe), gallium phosphide (GaP), indium phosphide (InP), copper... 

Single crystal silicon (sc-Si), polyciystalline silicon (p-Si), and amorphous silicon (a-Si) can all be used to make solar cells, with fabrication cost and device photoconversion efficiencies decreasing as one moves from single-crystal to amorphous materials. Various properties of these materials are summarized in Table 8.1. Other relatively common solar cell materials include gallium arsenide (GaAs), copper indiirm diselenide (CIS), copper indium-gallium... 

Many electronic companies in the State of California create a substantial volume of arsenic waste through the processing or manufacture of gallium arsenide (GaAs) microchips. Since the concentration of arsenic in wastewaters or sludges usually exceeds disposal limits for sewer and municipal landfills, these wastes are quite often treated and disposed to a Class I hazardous landfill. This practice is undesirable environmentally and economically as a long-term mechanism for waste disposal. 

How many grams of gallium are there in a 145-gram sample of gallium arsenide, GaAs ... 

There are 69-7 g of gallium, Ga (atomic mass 69-7 amu), in a 145-g sample of gallium arsenide, GaAs. Note that l45 g is the formula mass for this compound. 

A major advantage of the gallium arsenide (GaAs) laser is that it has the electron distribution of a semiconductor The main difference between electrons in semiconductors and electrons in other laser media is that in semiconductors all of the electrons occupy and thus share the entire crystal volume. Although all semiconductors possess this property, not all of them can be used as lasers. See Fig. 4. 

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