Fabrication of Si Textures with Low Etching Margin Using AgNO_3-assisted Alkaline Solution

摘要

An alternative method to fabricate crystalline Si (c-Si) textures with low etching margin using AgNO_3-assisted alkaline solution is reported. Recently, thin c-Si solar cells became the subject of the intensive studies thanks to the reduction of fabrication cost and also to some potential applications in flexible devices . The record efficiency for such solar cells of 19% using 43-μm-thick Si substrate is reported . However, decreasing the Si substrate thickness causes reduction of the amount of absorbed sun light, which requires the development of new approaches to fabricate the textured morphology on such thin c-Si wafers. The conventional methods for texture formation using anisotropic alkaline wet etching processes is incompatible with fabrication of thin c-Si solar cells due to the large etching margin (~ 20μm). Although employment of Ge mask deposited by gas source molecular beam epitaxy was successful to realize Si textures with low etching margin , wet process would be more preferable in terms of the cost reduction.