Lifetimes of organic photovoltaics: photooxidative degradation of a model compound

A poly phenylene vinylene (PPV-type) oligomer used in organic photovoltaics was designed to facilitate the interpretation of mass spectral data. A film of the oligomer was subjected to various degrees of illumination (1000 W m(-2), AM1.5) in air resulting in photooxidation of the material. The surface chemistry was monitored by TOF-SIMS and XPS. The experiment described accelerated photooxidation without any contributions from interface processes. The photooxidative degradation mechanisms are described starting from the intact molecule through presumably, intermediate photooxidation products to small photooxidation products. The processes are described with various degrees of specificity and with varying degrees of detail. Copyright (C) 2006 John Wiley & Sons, Ltd.