Large QLEDs with sputtered ZnMgO as an electron transport layer

We fabricated QD EL devices with a ZnMgO layer as an ETL by RF sputtering. The deposition condition of ZnMgO layer was optimized by controlling the partial pressure of oxygen and RF power for the best EL performance. Mg doping effectively reduced the defect sites induced by oxygen vacancy and the charge balance in the EML of QD EL devices with a Zn0MgO layer deposited by RF sputtering was dramatically improved by the controlled injection of electrons, which was resulted from the upshift of the conduction band minimum. As a result, large QD EL devices with an inverted structure showed the maximum luminance and current efficiency of 136,257 cd/m2 and 20.7 cd/A, respectively.