2. Experimental details
2.1. Materials
Diethyl Zinc (DEZ) (Zn(CH2CH3)2, 95% purity, CAS: 557-20-0) and
Trimethylaluminum (TMA) ((CH3)3Al) 98% purity, CAS: 75-24-1)
were obtained from Sigma Aldrich. Silicon wafer p-type (100) and
glass substrates were purchased from MEMC Korea Company and RS
France respectively.
2.2. Synthesis of Al2O3/ZnO ultrathin nanolaminates
Silicon and glass substrates were pre-cleaned in acetone, ethanol
and deionized water. A custom made ALD reactor was used for the synthesis
of ultrathin Al2O3/ZnO nanolaminates. ALD was performed using
sequential exposures of TMA (DEZ) and H2O separated by a purge of
argon with a flow rate of 100 sccm. The deposition regime for ZnO
and Al2O3 consisted of 0.1 s pulse of TMA (DEZ), 30 s of exposure to
TMA (DEZ), 30 s of purge with argon followed by 2 s pulse of H2O,
30 s of exposure to H2O and finally 40 s purge with argon. Al2O3/ZnO ultrathin
nanolaminates with different number of cycles were deposited
both on Si substrates and glass substrates by ALD (Table 1), the temperature
was fixed to 100 °C