Atomic layer deposited zirconium oxide electron injection layer for efficient organic light emitting diodes

作者：Vasilopoulou Maria^*; Kennou Stella; Ladas Spyridon; Georga Stavroula N; Botzakaki Martha; Skarlatos Dimitrios; Krontiras Christoforos A; Stathopoulos Nikolaos A; Argitis Panagiotis; Palilis Leonidas C

来源：Organic Electronics, 2013, 14(1): 312-319.

DOI：10.1016/j.orgel.2012.10.006

• Organic light emitting diode (OLEDs)
• Electron injection layer
• Zirconium oxide (ZrO2)
• Atomic layer deposition (ALD)

In this work, we demonstrate efficient polyfluorene-based light emitting diodes on which conformal, thin ZrO2 layers, formed by atomic layer deposition at a relatively low temperature (175 degrees C), in order to avoid introducing any damage in the organic under layer, efficiently inject electrons from their high lying conduction band to the polymer%26apos;s LUMO. An optimal thickness of 2 nm for ZrO2 results in a threefold improvement in luminous current efficiency compared to the reference device. The relationship between the thickness of the ZrO2 layer and the device operational characteristics is further investigated and the possible reasons for the improved device performance are discussed based on the experimental results obtained by a combination of photoemission spectroscopy and electrical/optical measurements.

• 出版日期2013-1