Transparent car roof is light source at night

BASF and Philips have developed an OLED car roof that can flip between acting as a window and a light source, giving light when switched on but becoming transparent when turned off.

The OLED (organic light emitting diode) roof can be combined with equally transparent solar cells, enabling it to power itself. When it’s off, the solar cells gather power for later use.

“This combination allows the driver to enjoy a unique open-space feeling while it generates electricity during the day and pleasantly suffuses the interior with the warm light of the transparent, highly efficient OLEDs at night,” says Dr Felix Görth, head of OLEDs and organic photovoltaics at BASF Future Business.

The OLED light sources are just 1.8 millimeters thin and can be transparent. Because the entire surface of an OLED lights up with diffused light, it’s a softer light source and produces less harsh shadows than point light sources. OLED’s also very energy-efficient.

The two companies have been working together on this and similar projects since 2006. The work is very much a demonstration project, and no commercial tie-ups have been announced.


“This project provides impressive evidence of new possibilities with OLEDs,” says Dr Dietrich Bertram, general manager of OLED Lighting at Philips.