Review on the progress of colored silicon solar cells for building-integrated photovoltaics (BIPV) application

Building Integrated Photovoltaics (BIPV) serves as a critical technology to tackle the space constraint issues in urban areas for installing solar panels and increasing land prices which increases the energy production cost − both of which are significant impediments to the net-zero carbon emissions goal. Net-zero Energy Buildings (NZEBs) are a promising prospect to drive the net-zero carbon emissions journey of urban spaces. The traditional solar modules are installed only on rooftops, limiting their energy production due to lesser rooftop area in urban areas, thereby under-utilizing the surface area obtained from the entire building. Incorporating these modules into building architecture can result in higher energy generation, however posing a major aesthetic bottleneck since these panels are only blue or black in color. Colored solar module is a promising method that can address this problem and provide impetus to BIPV. Silicon (Si) solar cell is the dominant solar technology with a proven record of long-term reliability and an established life cycle of over 25 years, making it a good candidate for colored solar cells. Efforts are underway to develop technologies that can enable colored Si cells, thus enhancing their prospect in BIPV technology. This review provides a comprehensive account of the current techniques used to impart color to Si solar cells which involve anti-reflection coatings (ARCs), dielectric mirrors, luminophores, quantum dots (QDs) and Mie-resonant nanostructures. We also discuss commercially available Si BIPV products and their cost analysis to offer insights into the current economics of colored Si modules.