While the technology of organic light-emitting diodes (OLEDs) is now very well established with OLEDs mass produced in the displays of smart phones and televisions, organic laser diodes have proven to be extremely difficult to demonstrate, despite significant research efforts over the last 30 years. Achieving direct injection lasing in an organic semiconductor is very difficult because the injected charges often form non-emissive triplet excitons which absorb light across the luminescence spectrum of the material.

Here we address this grand challenge of organic electronics by integrating a semiconducting polymer laser cavity into the substrate of a pulsed blue OLED of exceptionally high light output [1]. Under an electrical drive with pulses of a few nanoseconds, the integrated device generates the highest peak power density reported for OLEDs.  The electroluminescence internally pumps a population inversion in the green light-emitting polymer. A carefully designed diffraction grating in the laser waveguide provides distributed feedback of stimulated emission in the plane of the film, while diffracting a green output laser beam from the surface. 

While organic semiconductor devices are widely thought to be a slow optoelectronic technology, we show that these materials can access a very fast and intense operating regime, comparable to III-V microLEDs. This new regime of operation for OLEDs still needs better understanding of the underpinning materials and device physics, but offers new application areas in sensing, metrology and communications.  

[1]  K. Yoshida, J. Gong, A. L. Kanibolotsky, P. J. Skabara, G. A. Turnbull, and I. D. W. Samuel, "Electrically driven organic laser using integrated OLED pumping," Nature 621, 746 (2023).