All-inorganic quantum dot light-emitting diodes realizing a synergistically regulated carrier mobility dynamic equilibrium mechanism

Quantum dot light-emitting diodes (QD-LEDs) are promising for next-generation displays or lighting. Research on all-inorganic QD-LEDs that are suitable for high-temperature environments is still scarce even though QD-LEDs have demonstrated remarkable performance through organic–inorganic composite methods. A design for the synergistic adjustment of the carrier balance with a multi-layer controlled high-mobility electron transport layer and core–shell structure passivation of the emission layer is proposed from the perspective of charge-carrier dynamics in QD-LED devices. Accordingly, a non-toxic and low-cost all-inorganic ITO/NiO_x/ZnO@ZnS/ZnO/Al QD-LED device was successfully designed and fabricated by comparing the calculated results of the electron transport properties of various light-emitting layer materials in which the transport state of charge carriers in QD-LEDs was described by the balance of carrier mobility by combining the first-principles simulations of density functional theory and deformation potential theory numerical calculations. Experimental results of the luminescent performance are in excellent agreement with the simulation results. This QD-LED device design scheme can improve the electron/hole injection by directly finding the transmission material with the same energy level, which is far less difficult than balancing the charge carriers via changing structure. It provides a possibility for further optimizing the design of high-performance all-inorganic QD-LEDs.