Synergistic passivation for efficient thermally evaporated blue PeLEDs

luminescent properties and low cost. PeLEDs fabricated through thermal evaporation method could achieve pixelation and large-area uniform fabrication by using well-established fine metal masks. However, the performance of thermally evaporated blue PeLEDs still lag far behind. Optimizing the fabrication processes to enhance the efficiency of blue PeLEDs has become a pressing challenge that the global research community urgently needs to address.

Researchers led by Prof. Lei Wang at Huazhong University of Science and Technology (HUST), China, are interested in blue PeLEDs. By employing an innovative synergistic post-treatment modification technique, PEACl was first introduced for post-treatment, resulting in a highly stable 2D/3D perovskite film with low defect density. Subsequently, a layer of GABr was vacuum evaporated to enhance the film quality. Finally, the research team successfully fabricated blue PeLEDs with high efficiency and brightness, achieving a maximum external quantum efficiency (EQE) of 6.09% and a brightness exceeding 1325 cd/m². This represents a critical step toward the commercialization of full-color display technology.

The work entitled “Improved vacuum-evaporated blue perovskite light-emitting diodes with phenethylammonium chloride and guanidinium bromide synergistic post-processing modification” was published on Frontiers of Optoelectronics (published on March 24, 2025).