plant in Europe and "possibly in the world" is opened in France. 2019 – The world record for solar cell efficiency at 47.1% was achieved by using multi-junction concentrator solar cells, developed at National Renewable Energy Laboratory, Golden, Colorado, USA. This is above the standard rating of 37% for polycrystalline photovoltaic or thin-film solar cells as of 2018. It was reported in a study published in 2020. 2020s 2020 Solar cell efficiency of perovskite solar cells have increased from 3.8% in 2009 to 25.2% in 2020 in single-junction architectures, and, in silicon-based tandem cells, to 29.1%, exceeding the maximum efficiency achieved in single-junction silicon solar cells. 6 March – Scientists show that adding a layer of perovskite crystals on top of textured or planar silicon to create a tandem solar cell enhances its performance up to a power conversion efficiency of 26%. This could be a low cost way to increase efficiency of solar cells. 13 July – The first global assessment into promising approaches of solar photovoltaic modules recycling is published. Scientists recommend "research and development to reduce recycling costs and environmental impacts compared to disposal while maximizing material recovery" as well as facilitation and use of techno–economic analyses. 3 July – Scientists show that adding an organic-based ionic solid into perovskites can result in substantial improvement in solar cell performance and stability. The study also reveals a complex degradation route that is responsible for failures in aged perovskite solar cells. The understanding could help the future development of photovoltaic technologies with industrially relevant longevity. 2021 12 April – Scientists develop a prototype and design rules for both-sides-contacted silicon solar cells with conversion efficiencies of 26% and above, Earth's highest for this type of solar cell. 7 May – Researchers address a key problem of perovskite solar cells by increasing their stability and long-term reliability with a form of "molecular glue". 21 May – The first industrial commercial production line of perovskite solar panels, using an inkjet printing procedure, is launched in Poland. 13 December – Researchers report the development of a database and analysis tool about perovskite solar cells which systematically integrates over 15,000 publications, in particular device-data about over 42,400 of such photovoltaic devices. 16 December – ML System from Jasionka, Poland, opens first quantum glass production line. The factory started the production of windows integrating a transparent quantum-dots layer that can produce electricity while also capable