The effect of surface treatment on omni-directional efficiency of the silicon solar cells with micro-spherical texture/ITO stacks

A “bottom-up” surface texturing method based on nozzle-sprayed microspheres and spin-coated dielectric film has been proposed. The fill factor was improved by the use of indium tin oxide (ITO) as an antireflection coating (ARC) due to an increased effective area for carrier collection. The pretreatment using HCl prior to ITO deposition was found to suppress the formation of interfacial oxide at the ITO/Si junction. An enhancement in the short-wavelength response (400–600 nm) and an improvement in the short-circuit current (JSC) were accomplished. The difference in the efficiency (Δη) between the cells fabricated with ITO incorporating micro-spherical textures (MSTs) and those by KOH texturing was 13.5% at a light incident angle of 60°, comparatively larger than the difference in efficiency of 7.4% observed at normal incidence. These results demonstrate the superior omnidirectional antireflection property of the ITO+MST structure.

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► Using ITO as an antireflection coating improves fill factor of silicon solar cells.
► HCl pretreatment prior to deposition suppresses the formation of interfacial oxide.
► Cells with ITO+MST structure demonstrate superior omnidirectional antireflection.
► ITO+MST structure achieves better short-wavelength response and larger JSC.