Our technique uses a nanotexturing approach called Simultaneous Plasma Enhanced Reactive Ion Synthesis and Etching (SPERISE). It uses a common reactive ion etcher to create high density, high aspect-ratio nanocone array on the entire silicon surface. The texturized silicon solar cells have a light reflection of only ~1% (both wafer and thin film) and light transmission of only ~4% (thin film) in a broad band, which means they absorb around 95% of sunlight. This absorption enhancement property is also independent of light incent angle, which makes the solar cells omnidirectional absorbers so they can maintain the same efficiency regardless of the time of day.
Our nanotexturing technique is independent of crystalline orientation, thus effective for all four types of silicon solar cells. The nanocone array created by the SPERISE process also increases the effective surface area to 10 times larger than typical solar cells, which means more electricity can be generated per unit. Because of the above advantages, our prototype solar cell produced with the SPERISE nanotexturing technique obtained 22% efficiency enhancement over commercial solar cells, and our computer simulations indicate that over 40% enhancement is possible.
We are offering an exceptionally superior product, since our nanotexturing technique uses a single step process that permits ultrahigh-throughput, lithography-less, wafer-scale and room-temperature manufacturing to save on expensive equipment and control conditions. The technique also saves on production costs and appreciably increases the productivity of solar cell manufacturers' plants by combining conventional, multiple step anti-reflection strategies into a single step. In addition to the savings on machinery, utility, maintenance and labor costs, this technology also considerably reduces spending on hazardous disposal and waste water treatment fees, while lessoning the negative environmental impacts associated with conventional approaches.