THE INFLUENCE OF THE SPATIAL STRUCTURE ON THE ELECTRONIC-PROPERTIES OF POROUS SILICON - QUANTUM-CHEMICAL STUDY

In order to study the electronic properties of porous silicon (per-Si) we have investigated silicon nanoclusters with atomic configurations satisfying the general features of the radial and angular distribution functions of the per-Si structure modelled using the diffusion-limite d aggregation model. The electronic structure calculations were perfor med within the intermediate neglect of differential overlap approximat ion of the Hartree-Fock-Roothaan scheme. while the restricted configur ation interaction was employed in calculating excited states and trans ition rates. Both the electronic structure and optical transition stre ngth are found to depend strongly on the cluster size and local enviro nment. Importantly, the inclusion of many-electron effects is crucial in determining the transition rates. The low reactivity of some nanocl usters, together with their intermediate size and well-determined elec tronic properties, make them prospective initial blocks for the manufa cturing of optoelectronic materials with desired characteristics.