Semiconductor Nanoparticles in Zeolites

the semiconductor particles grown in a zeolite microporous crystal host will exhibit an apparent quantum size effect. 

In 1990, Canham reported the room-temperature luminescence of porous silicon.11111 This important discovery has attracted much attention towards an investigation in silicon with the quantum-size effect. Through chemical-vapor deposition, it is also possible to load silicon nanoparticles into zeolite channels and pores. First, disilane is treated with the protons in a zeolite and is grafted to the zeolite walls [Equation (9.13)]  

It is too ideal for one Cd4S4 nanocluster to occupy one sodalite cage. In the treatment of zeolite with H2S many mesoporous defects will be produced, and these mesoporous defects may accommodate larger cadmium sulfide clusters. Therefore, in the microporous crystal with a particular structure, there may exist many different cadmium sulfide particles with various sizes. However, the content of these cadmium sulfide clusters located defects is usually limited, and, as a result, they have little effect on the electronic spectral properties of the composite. Detailed composition and structural analysis indicates that the nanoclusters contain not only Cd and S, but also O. In fact, these clusters can be written as Cd4(S,0)4. 

Besides cadmium sulfide, other semiconductor particles can also be loaded in zeolite microporous crystals. Moller et al. prepared cadmium sulfide nanoparticles in zeolite Y through a similar approach.[117] Nevertheless, structural analysis indicates that the formed cluster particles are actually rather complex, and apart from cadmium sulfide clusters, there exist other nanoclusters such as Cd404 or Cd202Se in the channels of zeolite Y. These nanoclusters are not isolated, and they strongly interact with the framework oxygen of the zeolite. 

Hgl2 is also a typical semiconductor material, and it is also easy to vaporize after thermal treatment. Therefore, Hgl2 may be loaded into various zeolites through a vapor-transportation approach. Because of the confinement of the zeolite framework, Hgl2 in zeolites may exhibit distinct quantum-size effects. The electronic transition absorption spectrum of Hgl2 loaded in AlPOs-5 single crystals shows an apparent blue-shift, and in 

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