Although metal halide perovskite (MHP) light-emitting diodes (LEDs) have demonstrated great potential in terms of electroluminescence efficiency, the operational stability of MHP LEDs currently remains the biggest bottleneck toward their practical usage. Well-confined excitons/charge carriers in a dielectric/quantum well based on conventional spatial or potential confinement approaches substantially enhance radiative recombination in MHPs, but an increased surface-to-volume ratio and multiphase interfaces likely result in a high degree of surface or interface defect states, which brings about a critical environmentally/operationally vulnerable point on LED stability. Here, an effective solution is suggested to mitigate such drawbacks using strategically designed surface-2D/bulk-3D heterophased MHP nanograins for long-term-stable LEDs. The 2D surface-functionalized MHP renders significantly reduced trap density, environmental stability, and an ion-migration-immune surface in addition to a fast radiative recombination owing to its spatially and potentially confined charge carriers, simultaneously. As a result, heterophased MHP LEDs show substantial improvement in operational lifetime (T50: >200 h) compared to conventional pure 3D or quasi-2D counterparts (T50: < 0.2 h) as well as electroluminescence efficiency (surface-2D/bulk-3D: ≈7.70 ph per el% and pure 3D: ≈0.46 ph per el%).
|Publication status||Published - 2020 Jan 1|
Bibliographical noteFunding Information:
T.-H. Han and J.-W. Lee contributed equally to this work. This work was supported by the Air Force Office of Scientific Research (Grant No. FA9550-15-1-0610), the Office of Naval Research (Grant No. N00014-04-1-0434), and the National Science Foundation (Grant Nos. DMR-1210893 and ECCS-EPMD-1509955). This work was supported by the research fund of Hanyang University (HY-2019).
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering