Smart OLED Lighting on Electrochromic Glass

Smart organic light-emitting diodes (OLEDs) prepared on poly(3,4-ethylenedioxythiophene) (PEDOT)-based electrochromic glass is demonstrated for the first time. In this work, electrochromic glass based on PEDOT is adopted as a substrate for OLED and used for tuning the light-emitting direction. The color of the glass changes from pale blue to dark blue upon the application of an external voltage. The coloration or discoloration is due to reaction of the redox solution with PEDOT. Therefore, the utilization of this coloration or discoloration of the glass substrate can adjust the light-emitting direction of OLED. When the glass is tuned to semi-transparent, it causes the dual-side emitting device to display a graceful spatial impression. When the glass becomes highly opaque, the device exhibits top emission with a significantly enhanced luminance efficiency, in which the current efficiencies can be increased twice compared with those when the smart glass was switched off. For the green device, the current efficiency increases from 9.5 to 19.0 cd A(-1). For the white device, it increases from 7.5 to 15.5 cd A(-1). The authors believe that the combination of smart glass and OLED is a new concept for future OLED lighting applications.