Fabrication Of Nanostructured Silicon And Its Application On Silicon Solar Cells

Global energy and environmental crisis are becoming serious challenges for the sustainable development of human beings. Solar energy which is endless and environmental is attracting more and more attention, and the solar power has become an important energy providing proach and a new technology-intensive industry. So far, the silicon solar cells have made up the large majority of the market due to its low cost and stable performance. But it’s still a long way for us to live up with the large-scale applications of solar cells and more work should be done to reduce the cost reduction and increase the efficiency.It’s a trend to make the solar cell thinner to reduce the cost, but it will also affect the reflection. Low reflectivity is needed to absorb more light and improve the efficiency. Mental-assisted etching method is used to fabricate the reflection layer on the surface of silicon. Meanwhile, post-etching method is used to reduce the recombination caused by the nanostructure. The main innovative results are summarized.The evolution of the structure of the nanostructured surface and its reflection with the temperature, the reaction time, the size uniformity and the concentration of silver nano-particles are studied. The reflectivity will be lower with better uniformity of the silver nano-particles, and the fitful reaction time is 3-6 min. The reflectivity will reduce first and then increase as the reaction goes.The nanostructure will cause a serious recombination on the surface of the silicon, which leads to the lower efficiency of nanostructured solar cell compared to the commercial solar cell. In the paper, a post-etching method with the sodium hydroxide to the nanostructure is reported. The concentration of the alkali and the post-etching time are studied. An 18.35%-efficient nanostructured solar cell was fabricated successfully.Compared to p-type solar cells, n-type solar cells have higher efficiency. Therefore, it’s a better choice to apply the nanostructure surface on the n-type solar cells. With complex fabricating process and high cost, it’s a little difficult for them to be accepted by the industrial circles. In the paper, a new type nanostructured silicon solar cell was reported by us, it’s a nanostructured n+np solar cell with low reflectivity, high minority carrier lifetime and 17.7% efficiency. This new solar cell brings a effective solution to residual mental and surface recombination. Besides, the process of fabricating the solar cells with low cost can be well matched with industrial manufacture and shows a promising prospect for large-scale production.