This Small Business Technology Transfer (STTR) Phase I project aims to fabricate anti-reflective coatings (ARC) for solar energy applications. The approach is to use a convective and evaporation-induced assembly to deposit organized nanostructures and create sub-wavelength quasi repeating structures at lower cost than the repeating structures from photolithography. In this project, a Microreactor-Assisted Nanomaterial Deposition (MAND) system will be developed for solution-phase synthesis and large-scale manufacturing.
The broader/commercial impact of this project will be the potential to demonstrate a microreactor technology that can produce various films with defined structures and low cost. One of the major applications could be anti-reflective coating in solar systems to reduce light reflection and improve energy harvesting.
This Phase 1 effort undertook project activities to determine the technical and commercial feasibly of a new moth-eye nano-particle structured anti-reflective coating (ARC) for solar cell cover-glass (e.g. used in solar modules). Key findings support that this moth-eye ARC that has a) optical and mechincal performance exceeding existing industry solutions, and b) manufactorable as demenstrated by a fully scalable 6" substrate point-of-use prototype to coat glass surfaces. We also note that these efforts have contributed to CSD Nano to reach a commericalization milestone of sampling the ARC on solar cover-glass to a multi-national glass company for use in solar modules. At the highest level, the optical impact of our fabricated ARC is visually seen in the picture. Here, the increased light transmittance allows the color in the right-side glove to be more accurately seen. Applying to solar cells, the increased photon transmittance with the ARC recovers in multicrystalline Si an average quantum efficiency (QE) of 5.1% solar cell’s over bare glass across the 400nm-750nm spectrum (12 samples measured) and within 1.51% of ideal conditions (i.e. no glass cover). In another test, the power in monocrystalline PVs was increased 3.4% to 5.7% as measured in a solar simulator (2 samples). These results indicate that ability to increase solar module efficiency, a key factor for lowering solar energy costs. This project was organized around a joint collaboration between CSD Nano and Oregon State University where four multi-discipline teams undertook four major activities. The project effort started with nanoparticle (NP) synthesis methods to create the moth-eye structure building blocks, and then fabricating these structures into a film coating on glass using the synthesized NPs. The third activity was building a point-of-use prototype to demonstrate the feasibility of integrating the high-performance fabrication process and a microreactor to synthesized NPs into a scalable single unit. This shows a feasible method for industry manufacturing integration (i.e. works outside a lab). The fourth activity is measuring the moth-eye ARC optical and mechanical properties and comparing to the solar industry performances. We consider this Phase I effort a technical success and the feasibility results is a great encouragement towards pursuing commercialization effort for our moth-eye ARC towards a cheaper and more efficient solar industry.
