This project belongs to the field of solid state lighting.
The Outline of the National Medium-and Long-term Science and Technology Development Plan clearly lists "research on high-efficiency and long-life semiconductor lighting products" as the first priority theme (industrial energy conservation) of the first key area (energy) of the medium-and long-term plan. The National High-tech Research and Development Plan has established a major project of "Semiconductor Lighting Engineering" in the field of new material technology, focusing on supporting research on cutting-edge common and industrial technologies for semiconductor lighting. Phosphor preparation and device packaging are key technologies in white LEDs. In recent years, demand from the lighting consumer market has put forward new requirements and challenges for the research and development of phosphors and the packaging process of devices.
With the support of seed funds from the Shanghai City Science and Technology Commission and the Jiashan County County-level Science and Technology Plan project, more than 20 scientific researchers from relevant units have spent 8 years breaking through the traditional barrier to phosphor research and development. Through the structural design of luminescent materials and new preparation technology, they have achieved quantum efficiency improvement and spectral control, developed low-cost, high-efficiency phosphors with stable physical and chemical properties, and used innovative Flip-chip planar coating packaging technology. Realize the industrialization of high-quality white LED devices and are widely used in general lighting, landscape lighting, car taillights, backlights, street lights and other fields.
This project has the following main innovative contents:
(1) A non-dazzling yellow phosphor has been developed that cooperates with ultraviolet chips.
(2) A structural design model for composite group phosphors was developed. In the single-phase composite group phosphor, high-efficiency three-color (red, green, blue) emission with Ce3 +/Eu2 +/Eu3 + single doping and single-phase white light emission with Ce3 +/Eu2 +/Eu3 + co-doping are realized. The composite group phosphor structure design model can be widely used in the design and development of high-efficiency phosphors. The boron and calcium silicate composite group phosphor developed in this project only accounts for 3.2% of the rare earth raw materials, which can greatly reduce the production cost of the phosphor.
(3) Developed and developed oxide-based low-cost and high-efficiency red emitting phosphors used with GaN blue chips. The quantum efficiency reaches 19.3%, which is higher than similar nitride red phosphors, breaking through the lack of red light in the white LED fluorescent conversion system. Technical difficulties;
(4) Develop and use low-temperature Al reduction preparation technology to prepare phosphors and realize spectral control of phosphors.
(5) Use innovative flip-chip planar coating packaging technology to produce white LED lighting products with high cost performance and uniform light output.
The research results of this project have broken the intellectual property restrictions of foreign phosphors, especially the development of ultraviolet-excited complex group three-color phosphors and high-efficiency red powders suitable for use in blue chips. Some products have successfully replaced similar imported products; Innovate and improve the reduction preparation technology of phosphors, realizing the low-temperature Al reduction preparation of phosphors; develop flip chip planar coating packaging technology, which promotes the development of solid-state lighting. The core technology of this project has applied for 42 intellectual property rights, including 1 internationally authorized patent, 2 invention patents and 27 utility model patents; published 30 SCI papers, with a cumulative citation of more than 300 times; trained 1 doctoral student and 15 master's degree students.
At present, the key technologies and related products of this project have been applied, promoted and sold among users such as Shanghai Boen Stone Optoelectronics Co., Ltd., Hangzhou Yinghe Optoelectronics Materials Co., Ltd. and Zhejiang Yimi Optoelectronics Technology Co., Ltd., and have won recognition and praise from relevant users. The product or technology of this project has passed comprehensive testing by Shanghai City Semiconductor Lighting Engineering Center and Zhejiang Lide Product Technology Co., Ltd. Test Center, and its performance has reached the international advanced level. As a green energy-saving technology, this project has achieved a cumulative direct economic benefit of 177 million yuan in production over the past three years, achieving significant economic and social benefits.