Authors: Betul Canimkurbey, Furkan Isik, Savas Delikanli, Iklim Bozkaya, Emre Unal, Ahmet Tarik Isik, Zeynep Dikmen, Farzan Shabani, Ilayda Ozkan, Selin Piravadili, Hilmi Volkan Demir
Published: 2025-05-03
Source: Full article
AbstractQuasi‐2D semiconductor nanocrystals, also known as colloidal quantum wells (CQWs), with their high quantum yield in the visible range, ultra‐narrow emission, and in‐plane oriented transition dipole moments, provide potentially an excellent platform for flexible light‐emitting diodes (f‐LEDs). In this study, it is proposed and demonstrated colloidal f‐LEDs of a single layer face‐down oriented CdSe/CdZnS core/hot injection shell‐grown CQWs employed as an emissive monolayer in a flexible platform for the first time. The obtained f‐LEDs are shown to be immune to a large number of bending, enabled by the use of only a single emitter layer and their configuration all being face‐down in the layer. These f‐LEDs exhibit a maximum external quantum efficiency of 14.12%, an intense luminance of ≈33 700 cd m−2, a low turn‐on voltage of <2 V, and a highly saturated red color. Here, orienting these CQWs only in face‐down configuration is essential to efficient charge injection thanks to its extremely low roughness and increased outcoupling efficiency owing to in‐plane oriented transition dipoles. Therefore, these f‐LEDs of face‐down CQW monolayers, with their excellent luminance properties and stable emission, stand out as exceptional candidates for future advanced flexible display and lighting applications as well as wearables.