In this paper passivation layer of Al2O3 films prepared by liquid phase deposition on p-type (100) silicon substrate was investigated. The deposition solution of aluminum sulfate and sodium bicarbonate were used for Al2O3 deposition. The concentration of the sodium bicarbonate and boric acid in the deposition solution controls the rate of deposition of Al2O3 films. The optimal growth condition for the most effective film was pH value of 3.3. The best resulting of effective minority carrier lifetime and fixed charge density were 123.47 μs and -2.15×1012 cm-2 after anneal at 500°C in N2 atmosphere for 30 min. This passivation property has significant improvement that minority carrier lifetime increased by 41 times compared with bare silicon.
