Silicon nanostructured films are promising materials for photovoltaic applications, such as light-emitting diodes, light detectors and solar cells. By exploring confinement effects and changing the surface morphology, it is possible to vary the optical absorption threshold energy without the need to integrate different semiconductors. However, to exploit the potential of this class of materials, it is necessary to achieve a detailed understanding and control of n and p-type doping.
This project aims to a deeper understanding of the interaction of dopant atoms with the surface of free-standing silicon nanoparticles and other nanostructures. Density functional theory electronic structure calculations are our tool of choice, however we always aim to calculate observable properties will be applied to the interpretation of experimental results.
We believe it is possible to find the combination of dopant and surface passivation treatment that leads to optimum n- and p-type doping efficiency. Our recent results show why.
About Alexandra Carvalho
Alexandra holding crystals in the beach
A Marie-Curie Fellow at the University of Aveiro Portugal, she investigates problems related to doping and defects in silicon nanostructures. Alexandra Carvalho received her first degree at the University of Aveiro, Portugal, in 2005. This was followed by a PhD at the University of Exeter, UK (2005-2008), where she investigated defects in semiconductors, and an incursion at the physics of ferroelectrics as a post-doctoral researcher at the EPFL, Switzerland. She moved to the University of Aveiro in 2010. Her research was recently distinguished with the “Incentive to the Research Award 2011″ by the Gulbenkian Foundation. She is specially interested in materials for solar cells, and other forms of energy harvesting. She sees theory through engineer’s eyes, always using modelling to find the answers that work – in practice.