The characteristics of organic light emitting diodes with Al doped zinc oxide grown by atomic layer deposition as a transparent conductive anode

摘要

Al doped zinc oxide (AZO) films, deposited by atomic layer deposition (ALD) were investigated for applying a transparent conductive oxide (TCO) layer as an anode for organic light emittingdiode (OLED) devices. AZO films with a thickness of 100 nm were deposited at various Al atomic ratios ranging from 0 to 5% at a deposition temperature (250°C). The optimum electrical properties: the carrier mobility, the resistivity, and the sheet resistance for the 2% AZO film were found to be 16.2 cm~2 V~(-1) s~(_1) 1.5 × 10~(-3)cm~(-3), and 217 OMEGA/sq, respectively. The red OLED devices were fabricated using AZO anodes utilizing the various Al atomic ratios; the electrical and optical characteristics were then investigated. The best luminance, quantum efficiency, and current efficiency were found in the OLED device using the 2% AZO TCO; the results were 16599 cd/m~2,8.2%, and 7.5 cd/A, respectively.