SBIR Phase I: Ultra-Thin Silicon Solar Cells for Lightweight Flexible High-Efficiency Photovoltaic Modules

这项小企业创新研究（SBIR）第一阶段项目的广泛影响将是支持社会对更多采用清洁可再生能源的需求。该项目将启用的新型高效、轻量、薄的光伏模块将是工厂与商业和工业建筑（C&amp；I）屋顶材料集成的理想选择。这将解决美国一半的C&amp；I屋顶市场（低坡金属屋顶），由于重量限制，风荷载影响和其他因素，现有光伏组件的服务很差。此外，通过减少安装材料和人工，以及简化系统设计、许可等，它将使屋顶光伏系统的总成本降低高达40%。这种颠覆性创新可以将C&amp；I光伏系统——目前美国三大光伏市场中最小的一个——转变为美国太阳能增长的关键驱动力。这种光伏组件产品非常适合美国制造。SBIR第一期项目将允许首次探索吸收剂厚度低于40微米的硅异质结太阳能电池。更高厚度的硅异质结太阳能电池已经达到了超过26.5%的世界纪录效率。对于该项目所针对的超薄硅设计，理论预测开路电压（Voc）至少为780mV，远远超过目前任何硅太阳能电池的记录。高挥发性有机化合物将减少光伏系统的电阻损耗，并最大限度地减少系统性能下降从高工作温度。在太阳能晶圆技术方面，这将是实现硅异质结太阳能电池的一种新的无角方法，从而产生一种新型的坚固的柔性薄光伏组件，与目前的柔性薄膜光伏组件相比，具有更高的效率、更高的可靠性和更低的成本。在这个一期项目中，我们的目标是Voc至少为720mV。我们还将研究优化硅异质结太阳能电池的后反射器设计，以最大限度地提高薄硅吸收层的光吸收。最后，我们将为这种太阳能电池设计确定一个详细的实现24%效率的路径。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact of this Small Business Innovation Research (SBIR) Phase I project will be to support the societal need for higher adoption of clean renewable energy. The new kind of high-efficiency, lightweight and thin photovoltaic modules that will be enabled by this project will be ideal for integration at the factory with roofing materials for Commercial and Industrial (C&I) buildings. This will address half of the U.S. C&I rooftop market (low-slope metal roofs) that is poorly served by existing photovoltaic modules due to weight limits, wind-loading effects and other factors. In addition, it will drop total C&I rooftop photovoltaic system cost by up to 40% through reduction of installation materials and labor, as well as simplification of system design, permitting, etc. This disruptive innovation can turn C&I photovoltaic systems--today the smallest of the 3 major U.S. photovoltaic market segments--into a key driver for US solar growth. This photovoltaic module product is ideally suited for US manufacturing. The SBIR Phase I proposed project will allow the first ever exploration of Silicon heterojunction solar cells with absorber thickness substantially below 40 microns. Higher thickness silicon heterojunction solar cells have already achieved world record efficiency of over 26.5%. For the ultra-thin silicon design targeted by this project, theory predicts an open circuit voltage (Voc) of at least 780mV, well in excess of current records for any silicon solar cell. High Voc will reduce photovoltaic system resistive losses as well as minimizing system performance degradation from high operating temperatures. With respect to solar wafer technology, this would be a new kerfless approach to realizing silicon heterojunction solar cells, leading to a new type of robust flexible thin photovoltaic module, with much higher efficiency, superior reliability, and lower cost compared to current flexible thin film photovoltaic options. In this Phase I project we will target Voc of at least 720mV. We will also investigate optimizing the rear reflector design for silicon heterojunction solar cells, to maximize light absorption in the thin silicon absorber layer. Finally, we will identify a detailed path forward to 24% efficiency for this solar cell design.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.