[26a-F408-1~9] 16.3 シリコン系太陽電池

[26a-F408-8] Silicon nanopyramid texture fabricated by one-step solution process and its application to silicon heterojunction solar cells

〇(D)李 雨晴^1,2、齋 藤¹、松井 卓矢¹、宇佐美 徳隆² (1.つくば産業総合研究所、2.名古屋大学)

キーワード：シリコン、ナノ構造、太陽電池

A novel method to fabricate crystalline silicon (c-Si) nanometer-sized pyramid (nanopyramid) texture with low etching margin using one-step solution process is reported. Recently, thin (<120 μm) c-Si solar cells have attracted much attention as a promising way to significantly cut down the production cost of the solar cell modules [1-3]. Compared to the conventional micron-sized Si pyramids, the nanopyramid texture is advantageous particularly for thin c-Si solar cells in minimizing the etching margin. At the same time, a smaller pyramid size allows to narrow the screen-printed Ag fingers, which in turn improves the J_sc of solar cells and reduces the Ag consumption [4]. Furthermore, Si nanopyramid texture is expected to be suited to perovskite/Si tandem cells [5], as it offers the potential of conformal deposition of perovskite top cell on top of the textured Si surface by means of low-cost solution-based deposition techniques.
In this contribution, we propose a new methodology of fabricating Si nanopyramid texture featuring both excellent anti-reflection performance and relatively low etching margin using an AgNO₃-assisted alkaline solution. Si nanopyramids with a height of 300-500 nm were successfully formed on the Si surface. The etching margin of this structure was 3.4 μm. An even lower optical reflection is realized in comparison with the reference micron-sized pyramid texture . Si heterojunction solar cells with Si nanopyramid textures were fabricated, demonstrating higher J_sc and efficiency compared with the cells with the conventional micron-sized Si pyramids.