Quantum-size effects - theoretical

Stroyuk AL, Kryukov AI, Kuchmii SY, Pokhodenko VD (2005) Quantum size effect in semiconductor photocatalysis. Theoretical and Experimental Chemistry 41 207-228... 

This is usually referred to as the quantum size effect. Considerable experimental and theoretical efforts have been devoted to this subject and are reviewed in Section II. 

Theoretical calculations have been extended to study the shape dependence of the quantum size effect [48], The effect of covering semiconductor nanoclusters with another semiconductor (heterostructure) was also examined [49]. All of these calculations are based on effective mass approximation. 

The discrete molecular cluster species presented are ideal subjects for the study of the molecular quantum size effect [1], which is one of the most important questions prompting research in this area of cluster chemistry. It is necessary, therefore to explore the electronic properties of the cluster species, beginning with the interplay of cluster size and HOMO-LUMO gap. A number of theoretical investigations have provided the preliminary answers to this question [2, 3]. The first dipole- and... 

Recently, many researchers have studied fine particles or microcrystals to clarify the intermediate state between bulk crystals and isolated atoms and molecules (12-16). From these studies in the field of nonlinear optics, Hanamura predicted excitonic and surface-state enhancements of third-order optical nonlinearity in microcrystals because of quantum confinement effects, which is one of several size effects theoretically established by Ekimov et al. and Brus (17-19). Following these theories, enhancements of have been reported in semiconductor-microcrystallite-doped glasses and polymers (20,21). Organic microcrystals, however, have attracted very little attention so far (22,23) owing to the difficulties of preparing them. 

Nano-composite materials with fine semiconductor particles dispersed in the matrix have attracted considerable interest because the properties of the particles are much different from their bulks when the diameters are l s than the Bohr exciton radius. Such particles, which are generally named as nano-particles, are characterized by non-stoichiometric surface structure and quantum size effect 2). These properties would lead to new phenomena, new theoretical insights, and new materials and devices. 

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