Photobiologically Safe High Color Rendering Index White Organic Light-Emitting Devices

A high color rendering index (CRI) white organic light-emitting devices with photobiological safety is demonstrated. The effect of the active layer thickness on CRI and blue light hazard is demonstrated. The optimized device shows a high general CRI of 97, a special CRI
R
$_{9}$
of 94, and a power efficiency of 15.2 lm/W. The correlated color temperature is 2161. The device could be classified into low risk group at
$\sim 2000$
cd/m
$^{2}$
, which is proved to be safe for our eyes and could be applied to indoor illumination.