This Small Business Innovation Research Phase I project proposes to develop and deliver a high-throughput low-cost nanomanufacturing technology for making high-density high-uniformity omnidirectional-antireflection nanostructures on the entire surface of single crystalline and multicrystalline silicon solar wafers. Currently the optical reflection from solar cell surface is accounted for a significant loss in the photoelectric energy conversion process and thus better solar wafers with nearly zero optical reflection across a broad range of incident light wavelengths and angles will help to considerably improve the performance of solar cell devices and potentially bring down the solar electricity cost. The silicon nanostructures created by this unique processing method on solar wafer surface developed in this project will have superior antireflection and light trapping property. In this project the solar industry compatible nanomanufacturing method for zero-reflection ?Omni Black? solar wafers will be developed and the underlying processing physical mechanism will be better understood and controlled.
The broader impact/commercial potential of this project is to provide improved product and manufacturing technology for the solar industry and bring nanotechnology inventions from university laboratory to the commercial applications in industrial productions of high-performance solar cells. The proposed nanomanufacturing technology is a large-scale batch nanofabrication process, can be scaled up to simultaneous productions of a large quantity of solar wafers with nanostructured surface at industrial standard high production rate, and may be readily translated into current solar cell manufacturing industry in U.S. Cheaper and yet high-performance solar panels can be produced with the adoption of the advanced nanoscale manufacturing technology to be developed in this project, which makes the photovoltaic energy cost in U.S. more affordable and competitive. The efforts combining nanotechnology and renewable energy in this project will also be able to potentially create new manufacturing jobs in U.S. by translating new industrial production technology inventions from laboratory to factory.
Minimization of surface reflection and enhancement of light absorption is a very important approach to increase the efficiency of solar cell and reduce the cost of solar power. This Small Business Innovation Research Phase I project investigated a high-throughput, low-cost nanomanufacturing technology for super antireflective black silicon solar wafer production at industry scale. The solar cells produced with this process have not only up to 1% absolute efficiency enhancement, but also omnidirectional sunlight absorption of nearly 100% and around 20% daily energy yield increase. In addition, the nanomanufacturing process developed in this project is a disruptive dry plasma-based process to replace the conventional wet-chemical based process, which reduces the environmental impact of the solar cell production, minimizes the waste of silicon raw materials, and enables the tighter process binning. This Phase I project successfully met the four anticipated milestones by carrying out the nine carefully-planned tasks, demonstrated the controllability and reliability of the proposed nanomanufacturing process for the industry-standard 125 mm × 125 mm or 156 mm × 156 mm solar wafers, and gained the deterministic manufacturing control by fine-tuning the processing conditions. In addition, through six-month no cost extension, we fabricated prototype solar cells under semi-industrial environment, and demonstrated both peak efficiency boost and lower product variation. The findings, knowledge, and proof-of-concept obtained in the Phase I project confidently proved the feasibility of the proposed nanomanufacturing process for industrial high-volume PV manufacturing with satisfactory yield, throughput and robustness. Broadly, achieving higher quality and cheaper solar modules by applying a cutting edge translational nanotechnology to PV manufacturing makes the solar power more competitive, affordable and mass-producible in U.S., potentially reducing the carbon footprint of energy consumption. Moreover, innovating in PV manufacturing process helps ensure the America’s technology leadership in PV industry, and contributes to the strategic plan of bringing manufacturing back to the United States.
