Silicon etching significantly improves solar absoption

The two biggest challenges facing the development of photovoltaic solar cells are cost and efficiency. Solar cells are still relatively expensive to fabricate, mostly due to the cost of crystalline silicon used to produce the majority of these cells. What's more, solar cells are still relatively inefficient; they only capture a small amount of the energy from the sunlight that passes through them. Recently, researchers at MIT have demonstrated a relatively simple technique to dramatically increase solar cell efficiency while at the same time reducing the amount of material required. They use an inexpensive etching technique to carve microscopic inverted pyramids into thinner layers of silicon, exposing more surface area to the incoming sunlight. Their technique could facilitate the manufacturing of efficient thin-film solar cells.