Silva, E. L.Santos, M. C.2015-11-232015-11-2320132183-6000http://hdl.handle.net/10400.8/1427Since much attention is being drawn to nano-optoelectronic devices, with promising technological and medical applications (molecular photosensitization, colour-dyes, new generation of solar cell applications, Li-ion batteries), the understanding of the electrical and optical properties of hydrogen-passivated silicon nanocrystals (Si-NC) becomes an important aspect to focus upon, due to the fact that these systems possess different properties from those of the bulk materials. Nanostructures, smaller than macroscopic objects (present-day electronic devices), but larger than molecules, which description belongs to a complex domain of quantum mechanics, where amazing properties emerge. Quantum effects become dominant when the nanometre size range is reached, thus accounting for changes in the physical properties of nanostructures, as is the case for the increase in surface area to volume ratio altering mechanical and thermal properties of materials. Here, the geometry of the material can dictate drastic effects on quantized states.engjournal article