FREAパンフレット（英語）

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0200400600800x (mm)0200400600800y (mm)2.52.01.51.00.50.0x1013EL rateper area(photon / s cm2)624.5627.0627.2627.6627.5631.1631.1631.0630.9630.1627.3627.6627.0626.6629.3628.0630.1629.8628.2629.1626.9626.9628.2627.2624.6Values are Voc (mV) via ELEquivalent to commercialelectricityEquivalent to generalpower sources23 JPY/kWh14 JPY/kWh7 JPY/kWh・Improvement in efficiencies and cost-down・Application of the technologies developed in the previous projects・Novel materials and structures・Application of novel technologies for mass-productionSystem (example)・Module efficiency: 25%・Utilization factor: 15%・Operation period: 30 yearsSystem (example)・Module efficiency: 22%・Utilization factor: 14%・Operation period: 25 yearsCost[JPY/kWh]20132015202020252030012Research TargetA large number of photovoltaic (PV) systems have been installed under the Feed-In Tari (FIT) since July 2012.In addition to the conventional installation on house rooftops, many large-scale or “mega solar” power plants have been constructed. It is very important to reduce the cost of PV power generation in order to reduce the share of the burden on electricity users and to improve the competitiveness of PV modules in the market.Research OutlineAlthough crystalline silicon (c-Si) technology has the dominant share in the PV market, its cost must be reduced signicantly in order to accelerate the deployment of PV systems.The team conducts comprehensive research using a semi-production line from ingot slicing to module fabrication and testing.● Thin wafer fabrication technologyThe team is developing a slicing technology for thinner wafers with a thickness of about 0.10 mm (from the present cell thickness of 0.18 mm to 0.08‒0.10 mm).The team is also investigating the relationship between cracks and wafer strength to develop thin and tough wafers and to improve the yield during cell processes such as wafer cleaning.● Development of new cell fabrication techniquesNew cell production processes using the ion implantation technique have been developed in addition to the conventional thermal diusion process. The eective use of ion implantation can reduce the number of cell processes during back-contact cell fabrication.● Improvement in module reliability and development of a new evaluation methodA new nondestructive module evaluation method through voltage map-ping using the absolute electroluminescence (EL) method has been developed. A forward bias is applied to the solar cell and individual cell voltages can be evaluated based on the luminescence intensity of the cells.Japan’s PV roadmap for 2030 (NEDO PV challenges)Silicon ingot (left） and appearance after slicing (right)（wafer thickness: 0.12mm）Voltage mapping using the absolute electroluminescence methodThe team addresses the following subjects to develop technologies for producing low-cost, highly ecient and reliable modules (target conversion eciency: 22%)●Silicon ingot slicing technology with high accuracy and reproducibility (thin wafer)●High-eciency cell fabrication technique using thin Si wafers (PERC cell, back contact cell, etc.)●Technologies for improving the eciency and reliability of PV modules (development of new materials, structures, etc.)The team is also conducting research on “smart stack technology” to develop next-generation highly ecient solar cells (conversion eciency higher than 30%). Technologies to achieve the power generation cost target of 14 yen/kWh in 2020 and 7 yen/kWh by 2030 will be developed.Photovoltaic Power Team‒ High-Performance PV Modules Based on Thin Crystalline Silicon Solar Cells ‒Capturing Solar EnergyCapturing Solar Energy