Fabrication and a complete structural, optical and electrical analysis of porous germanium nanostructures embedded in a dielectric matrix: possibility of third generation solar cell applications


Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Faculty of Arts and Sciences, Department of Physics, Turkey

Approval Date: 2014

Thesis Language: English

Student: Burcu Altuntaş

Supervisor: RAŞİT TURAN

Abstract:

The primary goal of this thesis is to synthesize porous Ge nanostructures embedded in a dielectric matrix and perform a complete structural, optical and electrical characterization. Ge nanostructures can be a good candidate for use in third-generation solar cells, since they are alternative to Si nanostructures owing to their potentially higher photon conversion efficiencies. So far, most of the research is focused on the use of quantum dot structures in photovoltaic applications; although they provide quantum confinement of excitons, their drawback is the difficulties in electrical connection, which relies on tunneling probability through the dielectric matrix. As an alternative, we propose fabrication of porous Ge nanostructures embedded in a dielectric matrix via magnetron-sputtering technique, which is an interconnected Ge nanocrystal network where the electrical connection does not require any tunneling mechanism. We also suggest a way to preserve the quantum confinement effectby carefully tailoring the Ge content and engineering the structure of dielectric matrix.