Influence of surfactant addition for the texture etching process on multi-crystalline silicon wafer

Abstract

This study investigates the effects of different recipes and concentrations of surfactant on the texture and reflectance of a multi-crystalline silicon wafer surface. The morphology of the surface was examined and photographed using a field emission scanning electronic microscope. The reflectance of the surface was measured and analyzed using a self-designed optical system. The results of this study show that a higher hydrocarbon-surfactant (CH-surfactant) concentration in the etchant resulted in a slower reaction time. The optimum concentration of CH-surfactant was 1%. However, there were many white bubbles in the etching process. The optimum recipe for surfactant included fluoride 2% to diminish these bubbles. The reflectance was less than 22% in visible light. This cost effective acid chemical etching method is suitable for texturing silicon surfaces on 50 nm nanostructures. This is a critical criterion for determining the optimum recipe for surface texturing of acidic etching in solar cells.

Keywords:

• solar cell
• multi-crystalline silicon
• acidic texturing
• reflectance

Acknowledgments

This study was sponsored by funding from the National Science Council of Taiwan, NSC 98-2221-E159-013.