Holger Frauenrath: Polymer-Based Color Conversion Films
© 2011 EPFL
The excellence of the research performed at EPFL has once again been recognized at an international level. Holger Frauenrath has received a ERC Proof of Concept-2011 from the European Research Council (ERC).
Polymer-Based Color Conversion Films for White Lighting Devices
Energy efficiency in lighting devices is an active area of technology, aiming to reduce the growing human energy demand. Governmental regulations in industrialized countries call for a complete ban of incandescent electric light sources by 2020, to be replaced by more energy-efficient light sources such as devices based on light-emitting diodes (LED). At present, however, technology is needed that provides 'high quality' white light with a continuous emission spectrum at the required energy efficiency. In this context, the proposed project aims to develop polymer-based 'colour conversion films'. These films are supposed to be combined with blue LED light sources in order to produce cost-effective, energy-efficient, novel lighting devices with high white light quality. For this purpose, the colour conversion films will utilize a combination of two to four photo-chemically and thermally stable, polymer-substituted organic fluorescent dyes with complementary absorption and emission profiles. These dyes will be embedded into a polyiso-butylene (PIB) matrix to protect them from 'photo-bleaching' in the presence of water or oxygen. We will investigate the use of 'encapsulation layers' to further increase the device life time, and the application of an 'optical out-coupling' layer to enhance its efficiency.The goal of the project is to address the remaining technological issues and provide a proof of concept that multilayer films from the fluorescent dyes in PIB can be used to obtain inexpensive and durable colour conversion films to down-convert the emission from a blue LED light source into white light with a continuous emission spectrum. A prototype colour conversion film will ultimately be prepared by depositing layers of materials onto a polymer support, including the active colour conversion layer, optical in- and out-coupling layers to increase the efficiency of light emission, and encapsulation layers to further shield the colour conversion layer.
Max ERC PoC funding: 0.15 million Euros
Duration: 12 months
Host institution: EPFL
Project acronym: WHITELIGHT