Transparent CdSe/ZnS quantum-dot light-emitting diodes with WO_x/Ag/ WO_x transparent electrodes achieving higher efficiency than opaque quantum-dot light-emitting diodes

초록

High-performance transparent quantum-dot light-emitting diodes (TQLEDs) are achieved through fine-tuning the top dielectric/metal/dielectric (DMD) anode structure. The transparent DMD electrodes are utilized as both the bottom cathode and top anode of TQLEDs. Employing WO x /Ag/WO x DMD anodes serves a dual purpose of transparency and hole injection, thereby streamlining the TQLED design. Investigation into the effects of the thicknesses of WO x and Ag layers on the device characteristics reveals an optimal configuration of 10-nm WO x /27-nm Ag/40-nm WO x for the DMD anode. The resulting TQLED exhibits a remarkable device light transmittance of 47 % at 530 nm. With maximum bottom and top emission current efficiencies of 34.0 and 9.42 cd/A, respectively, the total emission obtained by summing the bottom and top emissions reaches the maximum current efficiency of 41.8 cd/A, surpassing that of conventional opaque quantum-dot light-emitting diodes. This advancement underscores the successful fabrication of TQLEDs boasting higher efficiency alongside substantial light transmittance.

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