Optically Pumped Lasing in Microscale Light-Emitting Electrochemical Cell Arrays for Multicolor Displays.

Laser displays, which offer wide achievable color gamut and excellent color rendering, have emerged as a promising next-generation display technology. Constructing display panels composed of pixelated microlaser arrays is of great significance for the actualization of laser displays in the flat-panel sector. Here, we report microscale light-emitting electrochemical cell (LEC) arrays that operate as both optically pumped lasers and electroluminescence devices, which can be applied as self-emissive panels for high quality displays. Optically pumped red, green, and blue laser emissions were achieved in individual circular microcells consisting of corresponding conjugated polymers and electrolytes, suggesting that the microstructures can act as resonators for coherent outputs. As-prepared microstructures possess a narrowed recombination region, which dramatically increases the current density by 3 orders of magnitude under pulsed operation, compared with the corresponding thin-film devices, representing a promising solution-processed device platform for electrical pumping. Under programmable electrical excitation, both static and dynamic displays were demonstrated with such microscale LEC arrays as display panels. The prominent performance of the demonstrated structures (microlaser arrays embedded in LEC devices) provide us deep insight into the concepts and device constructions of electrically driven laser displays.