Simple wet-chemical cleanings for high-efficiency silicon solar cell applications

Simple two-step wet-chemical cleans composed of an oxidizing step with in water dissolved ozone followed by an etching step have been studied for high-efficient hetero-junction silicon solar cell applications. For this purpose flat Si(111) samples passivated with amorphous silicon have been investigated. The effect of nano-roughness of the crystalline silicon surface on the minority carrier lifetime is shown. An influence of the storage time between cleaning and a-Si:H deposition was found and can partly be attributed to changes in surface roughness and native oxide growth.