SBIR Phase II: Transparent Molecular Photovoltaic Devices

This Small Business Innovation Research (SBIR) Phase II project will enable unprecedented freedom for architectural photovoltaic adoption by maintaining the aesthetics of existing building materials and the quality of natural indoor lighting. This unique approach offers to achieve levelized photovoltaic energy costs of 0.05-0.1 $/kWhr by (1) producing 10-40% of DC building electricity at the point of utilization, eliminating the need for DC-AC-DC power electronics, (2) simultaneously reducing building cooling demands 10-30% through rejection of infrared solar heat, increasing the effective PV efficiency by over 5% (absolute), and (3) piggybacking on the materials, installation, framing, customer acquisition, and maintenance of the existing building envelope, reducing non-module costs by over 50%. This project will also result in a core knowledge from which future generations of transparent photovoltaic devices and materials will be designed. Visibly transparent photovoltaics are also amenable to seamless energy harvesting within non-window surfaces such as electronic displays and mobile electronic accessories, enhancing the functionality of those products without impacting aesthetics or functionality. This Small Business Innovation Research Phase I project develops a transformational visibly transparent photovoltaic device. Building-integrated photovoltaics are a promising energy pathway to capturing large areas of solar energy and increasing US building efficiency at the point of utilization. However, the widespread adoption of such technologies is severely hampered by the cost and aesthetics associated with mounting traditional photovoltaic cells on siding and windows. In this project, these challenges are overcome by exploiting the excitonic character of molecular and organic semiconductors that lead to oscillator bunching to produce photovoltaic architectures with selective absorption, i.e. exhibiting visible minima and ultra-violet (UV) and near-infrared (NIR) maxima, uniquely distinct from the band-absorption of traditional inorganic semiconductors. By using excitonic molecular semiconductors with structured absorption in the UV/NIR these devices are simultaneously optimized for high power conversion efficiency, visible light transmission, and color rendering index.