White electroluminescence from perovskite-organic heterojunction

• Main Authors: Nur Fadilah Jamaludin, Natalia Yantara, Giovanni, David, Febriansyah, Benny, Tay, Yeow Boon, Salim, Teddy, Sum, Tze Chien, Mhaisalkar, Subodh, Mathews, Nripan
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Materials::Functional materials; Perovskite; Light-emitting Diodes
• Online Access: https://hdl.handle.net/10356/143322
• Institution: Nanyang Technological University

Despite extensive reports on red and green perovskite-based LEDs (PeLEDs), development of white PeLEDs remains limited by the low photoluminescence quantum yield of white-emitting perovskites and the undesired energy-transfer (ET) process occurring in multidomain Ruddlesden−Popper perovskites. While ET is beneficial for achieving efficient monochromatic emissions, the broadband spectrum required for white electroluminescence makes this phenomenon undesirable. Processing-induced physical separation of emitters has been proposed as an effective way to curb ET. Here, it is shown that by adopting a bilayered emitter configuration, achieved through a facile antisolvent-assisted spin-coating process, an increase in spatial separation between the blue perovskite and red-emitting organic species employed can be realized. This, in turn, has allowed for effective reduction of ET efficiency, leading to a record efficiency of 1.3%, the highest achieved to date from a perovskite-based white electroluminescent device.