Quantum dot light-emitting diodes with an Al-doped ZnO anode

摘要： A study of a hybrid ZnCdSeS/ZnS quantum dot light-emitting diodes (QLEDs) device fabricated with indium tin oxide (ITO)-free transparent electrodes is presented. Al-doped zinc oxide (AZO) prepared by magnetron sputtering is adopted in anode transparent electrodes for green QLEDs with different sputtering pressures. The Kelvin probe force microscopy measurement shows that AZO has a work function of approximately 5.0 eV. The AZO/poly(ethylene-dioxythiophene)/polystyrenesulfonate (PEDOT:PSS) interface can be adjusted by the sputtering pressures, which was confirmed by the hole-only devices. The AZO films with low surface roughness can form a good AZO/PEDOT:PSS interface, which can increase the holes’ injection, and result in improved charge balance. The maximum current efficiency, luminance and external quantum efficiency of the optimized QLEDs devices under a sputtering pressure of 1 mTorr can achieve values of 50.75 cd/A, 102,500 cd/m2 and 12.94%, respectively.