Thermal atomic layer deposited (ALD) Al2O3 films are applied at the front and rear sides of PERC-type c-Si solar cells. At the front side, Al2O3/SiNx as a double-layer antireflection coating reduces the reflection loss, and at the rear side, Al2O3 film as the passivation layer decreases the surface recombination velocity and enhances the internal reflectance at near-infrared (NIR) band together with SiNx layer. Due to the improvement in the reflectance combined with a decrease of the surface recombination velocity, the PERC solar cells show an improved Jsc by 0.2 mA/cm2 compared with the full-area back surface field cell.