BASF and Philips are developing a OLED car roof that is both light source and, when switched off, transparent solar cell.
"The OLEDs are transparent when switched off, allowing for a clear view outside the vehicle, yet providing light only within the vehicle when switched on," said BASF.
Transparent solar cells can be added to the transparent OLED sandwich structure.
"This combination allows the driver to enjoy an open-space feeling while it generates electricity during the day and pleasantly suffuses the interior with the warm light of the OLEDs at night," said Dr. Felix Görth, head of OLEDs at BASF.
BASF develops organo-chemical materials such as dyes that are used in the development and manufacturing of OLEDs by Philips.
The two firms have been cooperating since 2006 within the 'OLED 2015' initiative of Germany's Federal Ministry of Education and Research.
They are also key figures in the 'TOPAS 2012' project which was launched in January 2010, marking the second phase of OLED 2015.
TOPAS refers to 'thousand lumen organic phosphorescent devices for applications in lighting systems'.
In TOPAS 2012, consortium partners will focus on developing materials and component architectures as well as production machines for lighting-class OLEDs.