ИСТИНА

Our group pioneered in applying the ultrasonic spray pyrolysis (pyrosol) method to synthesize thin aluminum oxide AlOx films for surface passivation of crystalline silicon (c-Si). Passivation quality of AlOx was investigated for the rear highly doped p+ surface passivation of (n+pp+)c-Si solar cells. Films with a thickness of ~100 nm were deposited at a deposition temperature of 400 °C using a film forming solutions (FFS) based on a mixture of aluminium acetylacetonate in methanol. A deposition rate of ~50 nm/min was achieved, significantly higher than atomic layer deposition (ALD). The level of p+ surface passivation in this study was determined from measured rear internal quantum efficiency (IQE) curves. It has been found that the addition of water in FFS as well as the etching of the p+ surface significantly improved the passivation quality of the pyrosol AlOx. Rear IQE of ~95%, corresponding to the effective surface recombination velocity value of about 70 cm/s was achieved on highly boron-doped (~1020 cm-3) p-type surface