Study of Spin Dependent Transport Processes in Organic Solar Cells.

Abstract

This project aims to study the photo-excitation, recombination, dissociation and charges transport processes in highly original organic solar cells, based on thin films of Near Infrared (NIR) absorbing ionic dyes of the Cyanine class. A significant increase on the efficiency in converting solar energy into electricity is expected in these devices, since their physicochemical constitutions and architectures will be designed to broaden the spectrum of optical absorption. More specifically, it is intended to approximate the absorption band of solar cells for the near infrared, since this range includes a large portion of the intensity of solar energy. This project is linked to the project "Organic thin film solar cells based on near infrared absorbing colorants - BSJRP/CNPq", which is a bilateral cooperation between Brazil and Switzerland. Such partnership will show enriching for both parts. The Swiss group has the experience in the synthesis process and the engineering of these new photovoltaic devices, and, on the other hand, the Brazilian group has the knowledge on the characterization of spin dependent transport and recombination process in organic materials. For the purpose of this project, the characterizations will be performed on precursor materials and with mentioned devices by using sophisticated techniques for spin dependent transport phenomena study. Some of these techniques will be: Electron Spin Resonance, Light-Induced Electron Spin Resonance, Electrically Detected Magnetic Resonance and Electrical Impedance Spectroscopy with and without the presence of external magnetic field.