Light-Emission and Electricity-Generation Properties of Photovoltaic Organic Light-Emitting Diodes with RubreneDBP Light-Emission and Electron-Donating Layers

Abstract EN

We report the dependence of the characteristics of photovoltaic organic light-emitting diodes (PVOLEDs) on the composition of the light-emission and electron-donating layer (EL-EDL).

5,6,11,12-Tetraphenylnaphthacene (rubrene): dibenzo{[f,f′]-4,4′,7,7′-tetraphenyl}diindeno[1,2,3-cd:1′,2′,3′-lm]perylene (DBP) was used to form the EL-EDL, and C60 was used as an electron-accepting layer (EAL) material.

A half-gap junction was formed at the EAL/EL-EDL interface.

As the rubrene ratio in the EL-EDL increased, the emission spectra became blue-shifted and the light-emission efficiency increased.

The highest emission efficiency was achieved with an EL-EDL composed of 95% rubrene and 5% DBP.

The short-circuit current decreased as the rubrene content increased up to 50% and then saturated, while the open-circuit voltage was almost unchanged regardless of the rubrene content.

The power-conversion efficiency and fill factor increased as the composition of the EL-EDL approached that of pure materials.

By controlling the rubrene : DBP ratio, the emission color could be adjusted.

The emission efficiency of devices with mixed rubrene/DBP EL-EDLs could be greater than that of either pure rubrene or pure DBP devices.

We obtained an overall power-conversion efficiency of 3% and a fill factor greater than 50%.