Gallium arsenide, GaAs structure

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. 

When we combine elements that are closer in electronegativity, the bands contain contributions from both atoms. The so-called III-V compounds (which contain one element to the left of the carbon group and one to the right, e.g. gallium arsenide, GaAs) are of particular interest. These compounds adopt four-coordinate structures, e.g. zinc blende or wurtzite, which are similar to diamond but with each type of atom surrounded by four of the other type (Figure 8.12). 

An STM image of the atomic structure of gallium arsenide, GaAs (Ga, blue As, red). 

Thus far, we have considered the structure and applications of Si - the most heavily employed semiconductor. It should be noted that gallium arsenide (GaAs) is also widely used for FET applications since GaAs does not form a natural protective... 

Gallium(III) arsenide (GaAs) is not naturally occurring, but it is manufactured and extensively used as a semiconductor (Chapter 5). The crystalline structure of GaAs resembles sphalerite (ZnS, isometric, F43m space group), where each arsenic atom is coordinated by four gallium atoms (Klein, 2002), 339 (Bloss,... 

Gallium arsenide s native oxide is found to be a mixture of nonstoichiometric galhum and arsenic oxides and elemental arsenic. Thus, the electronic band structure is found to be severely disrupted, causing a breakdown in normal semiconductor behavior on the GaAs surface. As a consequence, the GaAs MISFET (metal insulator semiconductor field-effect transistor) equivalent to the technologically important Si-based MOSFET (metal-oxide semiconductor field-effect transistor) is, therefore, presently unavailable. 

Gallium arsenide nanowires with a zinc-blende structure were fabricated by laser ablation of GaAs powders mixed with GazOs (no metal catalyst used). SEM obser-... 

Determine the energies of the lowest three states in a gallium arsenide-aluminium arsenide quantum well structure in which the potential well has a width of 9.8 nm, corresponding to 30 GaAs layers. The electron effective mass is 0.067mg. 

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