Copper Iodide Based Hybrid Phosphors for Energy‐Efficient General Lighting Technologies

Abstract Solid‐state‐lighting (SSL) is a new lighting technology that is rapidly replacing conventional lighting sources because it is much more energy efficient, longer lasting, and contributes significantly to environmental protection. A main branch of SSL technology is light‐emitting diodes (LEDs), and white‐light LEDs (WLEDs) are in the greatest demand for general lighting and illumination applications. Current WLED devices rely heavily on rare‐earth elements (REEs), which will likely suffer from cost and supply risks and environmental consequences in the near future. Crystalline inorganic–organic hybrid materials based on I–VII binary semiconductors represent a promising material class as REE‐free phosphor alternatives. This article provides a brief overview of recent advancement on this material family, with a focus on the rational design, energy‐efficient and low‐cost synthesis, systematic modification, and optimization of their electronic, optical, and thermal properties. A particular emphasis will be made on our own progress over the past several years in developing four classes of CuI( L ) structures with substantially improved performance as energy‐saving lighting phosphors. General strategies for structural design, synthesis, and property optimization of these materials will also be discussed.