Singh Amandeep, Wolff Annalena, Yambem Soniya D, Esmaeili Mostafa, Riches James D, Shahbazi Mahboobeh, Feron Krishna, Eftekhari Ehsan, Ostrikov Kostya Ken, Li Qin, Sonar Prashant
School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Adv Mater. 2020 Mar;32(10):e1906176. doi: 10.1002/adma.201906176. Epub 2020 Jan 27.
Low-cost flexible organic light-emitting diodes (OLEDs) with nanoemitter material from waste open up new opportunities for sustainable technology. The common emitter materials generated from waste are carbon dots (CDs). However, these have poor luminescent properties. Further solid-state emission quenching makes application in display devices challenging. Here, flexible and rigid OLED devices are demonstrated using self-assembled 2D arrays of CDs derived from waste material, viz., human hair. High-performance CDs with a quantum yield (QY) of 87%, self-assembled into 2D arrays, are achieved by improving the crystallinity and decreasing the CDs' size distribution. The CD island array exhibits ultrahigh hole mobility (≈10 cm V s ) and significant reduction in solid-state emission quenching compared to pristine CDs; hence, it is used here as an emitting layer in both indium tin oxide (ITO)-coated glass and ITO-coated flexible poly(ethylene terephthalate) (PET) substrate OLED devices, without any hole-injection layer. The flexible OLED device exhibits a stable, voltage-independent blue/cyan emission with a record maximum luminescence of 350 cd m , whereas the OLED device based on the rigid glass substrate shows a maximum luminescence of 700 cd m . This work sets up a platform to develop next-generation OLED displays using CD emitters derived from the biowaste material.
采用源自废料的纳米发射体材料制成的低成本柔性有机发光二极管（OLED）为可持续技术带来了新机遇。源自废料的常见发射体材料是碳点（CDs）。然而，这些碳点的发光性能较差。进一步的固态发射猝灭使得其在显示设备中的应用具有挑战性。在此，展示了使用源自废料（即人发）的碳点自组装二维阵列制成的柔性和刚性OLED器件。通过提高结晶度和减小碳点的尺寸分布，实现了量子产率（QY）为87%的高性能碳点自组装成二维阵列。与原始碳点相比，碳点岛状阵列表现出超高的空穴迁移率（≈10 cm² V⁻¹ s⁻¹）以及固态发射猝灭的显著降低；因此，在此它被用作氧化铟锡（ITO）涂层玻璃和ITO涂层柔性聚对苯二甲酸乙二酯（PET）基板OLED器件的发光层，且无需任何空穴注入层。柔性OLED器件呈现出稳定的、与电压无关的蓝色/青色发射，最大发光强度达到创纪录的350 cd m⁻²，而基于刚性玻璃基板的OLED器件的最大发光强度为700 cd m⁻²。这项工作搭建了一个平台，用于开发使用源自生物废料材料的碳点发射体的下一代OLED显示器。
