A new family of luminescent materials that can be used to:
improve energy capture in solar panels improve laser efficiency customize spectrum of light-emitting diodes (LEDs)
The new materials may also be used to improve optical thermometry or the sensitivity of optical sensors.
The technology is available for licencing, along with the opportunity to partner with UiO’s research Groups.
Emissions characteristics of luminescent phosphors change with temperature, and luminescent phosphors have been used for optical temperature measurements since the 1980s: The phosphor is illuminated using a suitable light source, and the re-emitted light is analysed to yield accurate surface-temperature measurements.
Currently, the standard application method is to attach luminescent powders to the surface with a binder. This requires the development of individual processes for each combination of phosphor material, temperature range and surface type. The coatings also tend to be weak and provide short useful lifetimes. This has limited the use of phosphors for thermometry purposes.
UiO’s discovery is a new way of combining donor-acceptor pairs into well-functioning and robust luminescent materials, and a method for combining several independent materials into a standardized material pack with increased sensitivity.
Using a donor-acceptor pair is a common way of creating a luminescent material. A donor material such as YVO 4 is selected for its ability to absorb energy bearing photons. The material then passes the energy on to a suitable acceptor material (e.g. Pr 3+ ), which re-emits the light. Different combinations allow customized absorption and emission spectra.
Unfortunately, many desirable combinations do not work due to quenching, which is also the case for the YVO 4 :Pr 3+ combination. UiOs invention eliminates the relevant quenching mechanism, and the improved freedom to select donor-acceptor pairs makes it easier to design useful materials - for instance materials that can be exited with low-cost, low-energy LED lights.
The technology uses Atomic Layer Deposition (ALD) to coat a material with very thin epitaxial films of ceramic material. ALD-films have perfect contact to almost any surface, so the chosen material pack can be deposited on industrial components without further development, and becomes mechanically stronger and more resistant to vibration than powder coatings.
This means that we have a superior ability to engineer custom materials that fit a specific need, for instance a temperature-sensing material with high accuracy in a specific temperature interval. Being ceramic, the materials are suitable for high-temperature applications, resistant to abrasion and stable in chemically reactive environments.
The advantages of these materials are of a similar nature with regards to other applications: the value of luminescent materials has already been proven, and our new materials give improved design freedom with regards to luminescent properties, strength and durability.
The technology is protected by GB patent no 1708269.4 .