Graphene-Enhanced UV-C LEDs.
| Autor: | Meier J; Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstraße 81, 47057, Duisburg, Germany., Zhang H; Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstraße 81, 47057, Duisburg, Germany., Kaya U; Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstraße 81, 47057, Duisburg, Germany., Mertin W; Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstraße 81, 47057, Duisburg, Germany., Bacher G; Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstraße 81, 47057, Duisburg, Germany. |
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| Jazyk: | angličtina |
| Zdroj: | Advanced materials (Deerfield Beach, Fla.) [Adv Mater] 2024 Aug; Vol. 36 (32), pp. e2313037. Date of Electronic Publication: 2024 Jun 07. |
| DOI: | 10.1002/adma.202313037 |
| Abstrakt: | Light-emitting diodes in the UV-C spectral range (UV-C LEDs) can potentially replace bulky and toxic mercury lamps in a wide range of applications including sterilization and water purification. Several obstacles still limit the efficiencies of UV-C LEDs. Devices in flip-chip geometry suffer from a huge difference in the work functions between the p-AlGaN and high-reflective Al mirrors, whereas the absence of UV-C transparent current spreading layers limits the development of UV-C LEDs in standard geometry. Here it is demonstrated that transfer-free graphene implemented directly onto the p-AlGaN top layer by a plasma enhanced chemical vapor deposition approach enables highly efficient 275 nm UV-C LEDs in both, flip-chip and standard geometry. In flip-chip geometry, the graphene acts as a contact interlayer between the Al-mirror and the p-AlGaN enabling an external quantum efficiency (EQE) of 9.5% and a wall-plug efficiency (WPE) of 5.5% at 8 V. Graphene combined with a ≈1 nm NiO (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.) |
| Databáze: | MEDLINE |
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