SBIR Phase II: Quantum Confined Atom Based Nanophosphors for Future Efficient Lighting

这个小型企业创新研究(SBIR)第二阶段项目将涉及将单个原子量子限制在2至5 nm尺寸的三元半导体纳米晶体中，由此将开发出新的高效纳米荧光粉。纳米荧光粉的带隙工程可以改善发光特性，如吸收和发射光谱、半宽度、效率、寿命等。事实上，传统激活剂(稀土和过渡金属杂质)在纳米荧光粉中的作用可以根据不同的应用重新评估。具体地说，三元宽带隙半导体，如含银、铜、锰掺杂的硫化锌，提供了非常有效的接近白光的宽带可见光光谱。在三元半导体纳米晶体中进行带隙工程的可能性，类似于从III-V半导体发射光电子器件的可能性，为设计与LED和紧凑型荧光灯的激发光谱完全匹配的新的纳米磷光体打开了大门。这一发展将导致在这个第二阶段项目中出现一种新的白光光源。通过开发可被蓝光/紫外光LED激发的不同纳米荧光粉，成功地证明了纳米荧光粉不仅可以显著提高白光LED的性能，而且可以改善紧凑型荧光灯和弧光灯的性能。在商业上，这项纳米荧光粉工程的技术突破与当前的节能灯一起使用，预计将使LED的效率提高40%，灯具的效率提高15%。这些灯具整体能效的提高，将大大降低能源使用成本，预计到2025年将有助于节省相当于250亿美元的能源成本。

This Small Business Innovation Research (SBIR) Phase II project will involve quantum confining a single atom in 2 to 5 nm size nanocrystal of ternary semiconductor, from which new and efficient nanophosphors will be developed. The band-gap engineering of nanophosphors allows improvement in the luminescence characteristics such as absorption and emission spectra, half-width, efficiency, life-time, etc. Indeed the role of conventional activators (rare-earths and transition metal impurities) in nanophosphors can be re-evaluated for different applications. Specifically, ternary wide band gap semiconductors such as ZnCdS with dopants like Ag, Cu, Mn offer very efficient broad-band visible spectra that is close to white light. The possibility of band-gap engineering in nanocrystals of ternary semiconductors, similar to that catapulted the optoelectronic devices from III-V semiconductors, opens the door to design of new nanophosphors that match well with the excitation spectra of LED's and compact fluorescent lamps. This development would lead to a new class of white light sources in this Phase II project. By developing different nanophosphors that can be excited by blue/UV LEDs, it successfully demonstrates that nanophosphors can significantly enhance the performance of not only white LEDs but also can improve the performance of compact fluorescent and arc lamps. Commercially this technological breakthrough of engineering of nanophosphors when used with current efficient lamps, is expected to enhance the efficiency of LED's by 40% and lamps by 15%, respectively. These improvements in overall power efficiency of these lamps, will significantly lower the cost of energy used and it is projected will help to save energy costs equivalent to $25 billion by 2025.