How does light conversion happen with phosphors?
Visible light gathers all the electromagnetic waves that are detected by human vision. The visible spectrum, in the vacuum, is between 380nm and 750nm.
A Light-Emitting Diode, mostly known as LED, is an electronic device that emits light when crossed by an electrical current. The semiconductor, heart of the LED, emits in a narrow spectrum, often ranking the LED as a “monochromatic” emitter. There are mainly UV and blue native LEDs.
The conversion happens when a wavelength is transformed into another wavelength or more. The light conversion can be made either by a mix of powders dispersed in a matrix, or a ceramic convertor. Baikowski® provides Phosphors, designed for high performances of conversion. For blue LED conversion, our nano-phosphors are doped with Cerium. We can also add other dopants upon request.
Properties
Our phosphors show outstanding properties for various applications:
- Ceramic converters, unlike polymer matrix, allow high temperatures into the system, with very few alterations of the conversion and optimize diffusion. Ceramic converters are essential when it comes to high power LEDs and lasers.
- Embedded phosphors could require nanoscale material in order to answer the needs of new semiconductor design emerging (3D LED for example).
Baikowski’s YAGs and LuAGs are characterized by:
- High crystallinity, chemical purity, and optimized distribution of activators within the lattice allowing optimized optical properties (quantum efficiency…)
- Submicronic control of size & distribution, allowing a dense ceramic at low sintering temperature with the finest microstructure (low thickness & controlled light diffusion)
Moreover, we formulate YAGs and LuAGs products to unique customer requirements with a variety of dopants:
- Nd, Cr, Er, Yb… for laser applications
- Ce, Pr, Gd… for ceramic light converters & encapsulated phosphors
Applications
Light conversion phosphors are used in:
- High-power LEDs for automotive
- Lasers for wavelength conversion properties (undoped YAG)
- UV coatings in fluorescent tubes
- LEDs for display
Processability of Baikowski® powders
We provide nanophosphors and specialty powders for light conversion. Baikowski® products reach a high sintering reactivity without sintering aid. We make sure that activators are homogeneously distributed in the garnet lattice, to target maximum quantum efficiency.
Our powders adapt easily to the customer process:
- Hot Pressing & HIP (Hot Isostatic Pressing)
- Tape casting
- Slip casting
- Ceramic inkjet printing
- …