Author(s)

Néstor David Espinosa Torres, José Francisco Javier Flores Gracia, José Alberto Luna López, Juan Carlos Ramírez García, Alfredo Morales Sánchez, José Luis Sosa Sánchez, David Hernández de la Luz, Francisco Morales Morales

Research Center for Advanced Materials S.C. Unit Monterrey-PIIT, Apodaca, México.
Research Center for Semiconductor Devices, CIDS-ICUAP-BUAP, Puebla, México.
The Faculty of Chemical Sciences, BUAP, Puebla, México.

In systems in atomic and nano scales such as clusters or agglomerates constituted of particles from a few to less than one hundred of atoms, quantum confinement effects are very important. Their optical and electronic properties are often dependent on the size of the systems and the way in which the atoms in these clusters are bonded. Generally, these nano-structures display optical and electronic properties significantly different of those found in corresponding bulk materials. Silicon agglomerates found in Silicon Rich Oxide (SRO) films have optical properties, which have reported as depended directly on nano-crystal size. Furthermore, the room temperature photoluminescence (PL) of Silicon Rich Oxides (SRO) has repeatedly generated a huge interest due to their possible applications in optoelectronic devices. However, a plausible emission mechanism has not yet widespread acceptance of the scientific community. In this research, we employed the Density Functional Theory with a functional B3LYP and a basis set 6 - 31G* to calculate the optical and electronic properties of small (six to ten silicon atoms) and medium size clusters of silicon (constituted of eleven to fourteen silicon atoms). With the theoretical calculation of the structural and optical properties of silicon clusters, it is possible to evaluate the contribution of silicon agglomerates in the luminescent emission mechanism experimentally found in thin SRO films.

Nano-Crystals; Silicon Clusters; Silicon-Rich Oxide; Luminescence; Magic-Number

N. Torres, J. Gracia, J. López, J. García, A. Sánchez, J. Sánchez, D. Luz and F. Morales, "Ab Initio Molecular Orbital Calculation for Optical and Electronic Properties Evaluation of Small and Medium Size Silicon Nano-Clusters Found in Silicon Rich Oxide Films," Journal of Modern Physics, Vol. 4 No. 11B, 2013, pp. 1-26. doi: 10.4236/jmp.2013.411A2001.