We investigate here the optical properties of excitons in a large array of ordered semiconductor-insulator nanorods. A simple and elegant approach is described to obtain such semiconductor-insulator nanorod structures. Here, we investigate ZnS and ZnS:Mn nanorods of diameters ∼15–100nm crystallized within the pores of polycarbonate membrane. The nanorods confined in the dielectric matrix display strong ultraviolet (UV) excitonic absorption and emission bands in both undoped and Mn2+ doped samples. The data reveal that dielectric confinement rather than dimensional quantization has the significant effect in UV-visible optical absorption and photoluminescence (PL) processes in these semiconductor-insulator nanorods of sizes much wider than the Bohr radius. Interestingly, the emission band associated with Mn2+ transition (∼587–600nm) is also significantly affected by the size effect as well as dielectric discontinuity at the interface. A detailed investigation of PL emission from these embedded ZnS and ZnS:Mn nanorods is also reported.

The details of the electronic band structure of GaSbBi as functions of Bi mole fraction and along different symmetry directions of the crystal are calculated using a 14 band k.p model considering the band anti-crossing interaction between the valence band of the host III-V material and the Bi related impurity level resonant with the host. The effect of the lattice strain on the band structure as a result of incorporating a higher amount of Bi in the material is also studied. Variations of the bandgap energy, spin orbit split-off energy, band offsets, and the different sub-band energies are presented as functions of Bi content in GaSbBi as well as along the three symmetric k directions. Effective mass of the charge carriers and their dependence on Bi content is investigated. Furthermore, the intrinsic carrier concentration of the material as a function of Bi composition is evaluated. Finally, the optical absorption in the material is investigated considering the electronic transitions involving various valence sub bands and the conduction band.

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Oleyl amine capped CdSe quantum dots are allowed to form monolayer on aqueous HAuCl4 subphase and Langmuir–Blodgett technique is used judicially to grow Au tips in a directed fashion on CdSe quantum dots.

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