High Color Conversion Efficiency Realized in Graphene-Connected Nanorod Micro-LEDs Using Hybrid Ag Nanoparticles and Quantum Dots

In this paper, a uniform nanorod (NR) array is etched onto the surface of Micro-Light-Emitting-Diodes (mu LEDs) and mix Ag nanoparticles (NPs) with QDs to fill the gaps between the nanorods. Simultaneously, the study utilizes graphene to connect individual nanorods and enhance current spreading. The nanorod array's structure significantly reduces the distance between the QDs and the quantum well (QW), reducing energy loss from the excitation light source through a non-radiative energy transfer (NRET) mechanism. Additionally, the Ag NPs function as localized surface plasmons (LSPs), further enhancing the CCE of QDs via the absorption resonance. In this study, the effects of two types of Ag NPs are compared with different absorption resonance peaks on device performance. The results demonstrate that Ag NPs with absorption resonance peaks matching the emission wavelength of QDs play a more crucial role in the system. This configuration achieves a CCE of 77.78% for mu LEDs with nanorod arrays, operating at a current of 10 mA. Compared to the conventional mu LED structure with QDs only on the surface, the proposed method improves the CCE of mu LEDs by an impressive 86.5%. This outcome underscores the significant contribution of the NR structure and LSPs in enhancing the CCE of QD-mu LEDs. A hybrid quantum dot nanorod Micro-LED (QD-NR-mu LED) with LSPs assistance to enhance the CCE of hybrid mu LEDs. This study significantly improves the color conversion efficiency of QD-mu LEDs through non-radiative energy transfer and localized surface plasmon coupling, paving the way for full-color display of mu LEDs. image