Group III-V nitrides

The fundamental physical properties of nanowire materials can be improved even more to surpass their bulk counterpart using precisely engineered NW heterostructures. It has been recently demonstrated that Si/Ge/Si core/shell nanowires exhibit electron mobility surpassing that of state-of-the-art technology.46 Group III-V nitride core/shell NWs of multiple layers of epitaxial structures with atomically sharp interfaces have also been demonstrated with well-controlled and tunable optical and electronic properties.47,48 Together, the studies demonstrate that semiconductor nanowires represent one of the best-defined nanoscale building block classes, with well-controlled chemical composition, physical size, and superior electronic/optical properties, and therefore, that they are ideally suited for assembly of more complex functional systems. 

S. Nakamura, Group III-V Nitride Based Ultraviolet-Blue-Green-Yellow Light-Emitting... 

These two issues have contributed to extensive research on metal-organic precursors for the deposition of nitrides of metals in groups III-V. There has been considerable interest, as well as progress, in CVD of GaN and AIN because these materials have been in the technological spotlight recently, and their depositions involve similar chemistry. The synthesis of new precursors continues to proceed at a high rate. The precursor strategies that have resulted are summarized in several recent review articles " . 

Besides group IV, the compounds by the atoms in groups III-V are also semiconductors, such as BN, BP, Bas, AIN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb. Except for the nitrides, all of these compounds crystallize into the zincblende structure. The nitrides are stable in the wurtzite structure. Meanwhile, the mixrnre crystals made of binary III-V compounds also have semiconducting properties, such as (Ga,Al)As, Ga(As,P),(In,Ga)As, and (In,Ga)(As,P). 

Ponce, F.A. (1998) Structural defects and materials performance of the III-V nitrides, in Group III Nitride Semiconductor Compounds, (B. GU), Oxford University Press, Oxford,... 

The binary compounds of the Group 13 metals with the elements of Group 15 (N, P, As, Sb, Bi) are stmcturally less diverse than the chalcogenides just considered but they have achieved considerable technological application as III-V semiconductors isoelectronic with Si and Ge (cf. BN isoelectronic with C, p. 207). Their stmctures are summarized in Table 7.10 all adopt the cubic ZnS stmcture except the nitrides of Al, Ga and In which are probably more ionic (less covalent or metallic) than the others. Thallium does not form simple compounds... 

Diffusion in the Presence of Excess Point Defects. Oxidation-Enhanced Diffusion. Oxidation generally enhances the diffusion of group III and group V elements except for antimony (Figure 13). Oxidation-enhanced diffusion is generally observed by depositing a silicon nitride mask on the silicon surface that will prohibit oxidation in the regions that it covers. 

Inorganic non-oxide materials, such as III-V and II-VI group semiconductors, carbides, nitrides, borides, phosphides and silicides, are traditionally prepared by solid state reactions or gas-phase reaction at high temperatures. Some non-oxides have been prepared via liquid-phase precipitation or pyrolysis of organometallic precursors. However, amorphous phases are sometimes formed by these methods. Post-treatment at a high temperature is needed for crystallization. The products obtained by these processes are commonly beyond the manometer scale. Exploration of low temperature technique for preparing non-oxide nanomaterials with controlled shapes and sizes is very important in materials science. 

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