Canimkurbey Betul, Isik Furkan, Delikanli Savas, Bozkaya Iklim, Unal Emre, Isik Ahmet Tarik, Dikmen Zeynep, Shabani Farzan, Ozkan Ilayda, Piravadili Selin, Demir Hilmi Volkan
Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey.
Department of Physics, Polatlı Faculty of Arts and Sciences, Ankara Hacı Bayram Veli University, Ankara, 06900, Turkey.
Small. 2025 Aug;21(32):e2502314. doi: 10.1002/smll.202502314. Epub 2025 May 3.
Quasi-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, 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.
准二维半导体纳米晶体，也被称为胶体量子阱（CQW），在可见光范围内具有高量子产率、超窄发射以及面内取向的跃迁偶极矩，为柔性发光二极管（f-LED）提供了一个潜在的优秀平台。在本研究中，首次提出并展示了一种以单层面朝下取向的CdSe/CdZnS核/热注入壳生长的CQW作为发光单层的柔性平台中的胶体f-LED。所获得的f-LED仅使用单个发射层且其结构在层中全部面朝下，从而表现出对大量弯曲具有免疫性。这些f-LED表现出最大外量子效率为14.12%，高强度亮度约为33700 cd m，低开启电压<2 V，以及高度饱和的红色。在此，仅将这些CQW以面朝下的配置取向对于高效电荷注入至关重要，这归因于其极低的粗糙度以及由于面内取向的跃迁偶极而提高的外耦合效率。因此，这些面朝下的CQW单层f-LED，凭借其优异的亮度特性和稳定的发射，成为未来先进柔性显示、照明应用以及可穿戴设备的杰出候选者。
