A facile way to deposit conformal Al2O3 thin film on pristine graphene by atomic layer deposition

- It is difficult to deposit Al2O3 thin films on pristine graphene directly.
- H2O pulses pretreatment can enhance the Al2O3 coverage on pristine graphene.
- Uniform Al2O3 thin films can grow on the graphene after dipping pretreatment.
- No defects are produced in graphene after dipping pretreatment.
- It is easier to deposit Al2O3 on CVD graphene than exfoliated graphene.