PHOSPHORS FOR LED LIGHTING
The development of LED technology provides an opportunity for creating alternative light sources that are more efficient and longer lasting than traditional lighting. LEDs are used as indicator lights, turn signals, and as backlighting for screens. However, major energy savings will occur when this technology is used for in-home lighting. The most common method of creating a LED-based light bulb capable of in-home use is to use an LED light and inorganic phosphors (a material that absorbs and emits light). The phosphor absorbs the blue or near-UV LED emission and re-emits light at a longer wavelength (yellow). The combination of emission from the LED and phosphor creates the appearance of white light, illustrated on the right. Currently, a majority of phosphors used for white light generation lack emission in the red region of the visible spectrum causing most bulbs to produce a "cool" (blue-ish) light that is harsh to the human eye. Furthermore, the efficiency of the phosphors decreases as the operating temperature of the LED increases.
The Brgoch group develops novel phosphors based on oxide, oxynitride, and nitride materials that produce blue, green, and red photon emissions. The combination of these three colors with a UV LED can overcome many of the current issues with LED lighting. We focus on using numerous synthetic methods such as high-temperature reaction, rapid microwave-assisted reactions, and sol-gel chemistry to prepare the materials. The characterization of new phosphors involves X-ray and neutron diffraction as well as optical spectroscopy. The group also employs computation to interpret the efficiency as well as temperature dependent optical properties of our new materials.
Hewlett Packard Enterprise Data Science Institute SEED funding