Abstract: This invention is related to a new treatment process employed during preparation of the ZnO ETL in a QDLED. The treatment involves exposing the ZnO layer to fluorine (F). In embodiments of this invention, the exposure of the ZnO layer to the F is performed using a fluorine plasma environment (e.g., using CF4, CHF3, C4F8 or SF6). Alternatively, the F exposure may be done by exposing the ZnO ETL to a suitable fluorine-containing substance such as fluorine gas or fluorinated solvents. The F plasma treatment of the ZnO improves both QDLED device EQE and EL stability.