Light-emitting MOS junction for polarized electroluminescence from quantum rods

The anisotropic structure of CdSe/CdS quantum rods (QRs) produces highly linearly polarized emission. Achieving large-area electroluminescence with a high degree of linear polarization (DoLP) from QRs remains challenging. In this work, we propose a light-emitting metal/oxide/semiconductor junction (LE-MOSJ) featuring a greatly simplified ITO/insulator/QRs/Ag architecture, devoid of injection or transport layers, to realize polarized electroluminescence. In this device, a light-responsive azo dye (SD1) serves as an alignment layer on the electrode substrate, creating a highly aligned QR layer. This LE-MOSJ structure enables polarized luminescence from the QRs without requiring removal of the SD1 layer. Photoluminescence and electroluminescence DoLP values of 0.68 and 0.57 are achieved, respectively; the small discrepancy is attributed to the optimized device architecture. This strategy facilitates the fabrication of large-area, aligned QR arrays for stable electroluminescent devices and broadens their applications in optical communication, data encryption, and next-generation displays.