Ca test of Al2O3 gas diffusion barriers grown by atomic layer deposition on polymers

Abstract

Quantitative Ca tests were used to determine the water vapor transmission rate (WVTR) through 25nm thick Al2O3 gas diffusion barriers grown on plastic by atomic layer deposition (ALD). The measured WVTRs were 1.7×10−5g∕m2day at 38°C and 6.5×10−5g∕m2day at 60°C. Based on the apparent activation energy, the WVTR at 23°C is estimated to be only 6×10−6g∕m2day. The WVTR values for the Al2O3 ALD film are very similar to the WVTR value for the glass control. These Ca tests indicate that Al2O3 ALD gas diffusion barriers should enable display and lighting applications of highly moisture sensitive organic light-emitting diodes on plastic.