Scalable Bilayer MoS₂-Based Vertically Inverted p–i–n Light-Emitting Diodes

Herein, a vertically inverted p–i–n architecture of light-emitting diodes (LEDs) is designed for manufacturing feasibility and demonstrated scalable bilayer MoS₂-based LEDs. A 4 inch scale bilayer MoS₂ is prepared by a two-step growth method allocating the pre-deposition of a few-nm thick metal film and post-sulfurization. To apply bilayer MoS₂ for an active layer in LEDs, the film is transferred over ZnO nanoparticle layers, an electron transfer layer, and then the rest of the LED components are constructed by thermal deposition. This vertically inverted LED architecture allows individual organic or inorganic components to incorporate without degradation during the wet-transfer process and transfer electron or hole carriers across separate layers, resulting in efficient radiative recombination in the MoS₂ emitting layer. MoS₂-based LEDs exhibit electroluminescence of ≈5.41 cd m⁻² throughout four active areas of 6.25 mm² at a driving voltage of 7 V. Therefore, this achievement can overcome the drawbacks of existing transition metal dichalcogenides (TMDs)-based optoelectrical applications and extend its potential in various fields, such as flexible, ultrathin, or transparent displays.