Researchers at Seoul National University and Korea Advanced Institute of Science and Technology (KAIST) have developed highly efficient tandem perovskite light-emitting diodes (PeLEDs). This advancement may expedite the commercialization of perovskite light-emitting materials in next-generation display technologies.
The Ministry of Science and ICT (MSIT) announced that the team, led by Professor Lee Tae-woo from Seoul National University’s College of Engineering, has successfully created a high-efficiency and long-life hybrid tandem light-emitting device. This device combines metal halide perovskites with organic light-emitting diodes.
PeLEDs are traditionally less efficient than conventional organic light-emitting devices (OLEDs). Overcoming this hurdle requires a tandem structure that combines devices with distinct properties. However, integrating perovskite, which is processed in a solution form, with other devices has been challenging.
Professor Lee’s team has pioneered fabricating tandem-structured PeLEDs through an innovative design. This design creates a bottom layer of perovskite nanocrystal monolith via a solution process, topped with an organic light-emitting monolith formed through a deposition process. This marks the first successful attempt to produce a tandem light-emitting device based on perovskite. The team identified an optimal device structure that simultaneously delivers high efficiency and exceptional color purity, dubbing it ‘h(hybrid)-Tandem Valley.’
The newly developed hybrid tandem device significantly boosts light extraction efficiency. It utilizes a slender, transparent nanoparticle light emitter, enabling complete light transmission from the organic layer atop the perovskite layer. This tandem device has a lifespan of 5596 hours, a substantial improvement over the 1.8-hour lifespan of standard perovskite single devices.
Professor Lee highlighted the significance of this research, stating, “This study is crucial as it provides a blueprint for layering different light-emitting devices and arranging them to satisfy both efficiency and high color purity criteria.” He added, “Building on this foundation, we aim to develop not just green but also blue and red hybrid perovskite tandem devices, taking a step closer to achieving full-color hybrid tandem displays.”