Hybrid Nanophotochromic oxidized yttrium hydride films

Heat gain or losses through windows are responsible for 25-30% energy
uses due to cooling and heating. Multiple strategies are utilized in the world
to minimize the losses due to air leaks, poor thermal insulation and radiative
losses. The newly awarded project ?Hybrid nanophotochromic oxidized
yttrium hydride (YHO) film? through highly competitive and prestigious FRINATEK program of the Research Council of Norway aims to address
the challenge related to controlling the radiative losses to create energy
efficient windows. The project will be implemented by the Institute for Energy
Technology (IFE) in collaboration with the University of Uppsala, Sweden
and Istanbul Technical University, Turkey. The network intends to develop
the technology known as photochromic windows from hybrid materials
obtained by incorporation of inorganic nanomaterials into polymers. YHO
has been selected as inorganic nanomaterial that belong to emerging class
of materials called oxyhydrides with oxide and hydride anions sharing the
same sites in the lattice. The material exhibits photochromic properties at
room temperature and ambient pressure. While the nature of the effect
is still fundamentally unclear, they have already showed a great potential
for light-induced tuning of their transmittance from 90 to 50 %. However,
commercialization of the technology in its present stage is limited due to
ceramic nature of YHO, dependence of photochromic effect on angle of
incidence of sunlight, degradation, and worsening of the film adhesion
on the substrate. In addition, the preparation of the pure inorganic bulk
material requires a complicated deposition process than hybrid one. Taking
into account the limited availability of photochromic devices in the market,
the possibility to contribute with new material solutions reducing cost, as
proposed in the present project, is of high interest for the European industries
and will improve competitiveness and strengthened European industrial
leadership.

The Nanochromatics project aims to demonstrate a hybrid nanophotochromic material based on oxidized yttrium hydride (Y-H-O) nanoparticles
incorporated into a polymer. It has potential for a number of applications such as glass coatings for buildings and transportation to control the sunlight and heat transfer through glass. Alternative applications are in the medical
industry and environmental technology (as emitting and sensing devices) and in military - as coatings to reduce visibility to IR viewers. The hybrid films are expected to have numerous advantages over the organic counterparts by
enhanced durability, stability to UV radiation and sensitivity to humidity, and over the inorganic counterparts by independence on angle of incidence of sunlight, by enhanced transparency in the clear state and colorfulness, by faster kinetics of color change. The interest to Y-H-O is originates from its efficient photochromism,
which does not form midgap states blocking the visible light. However, for realization of the materials potential the following challenges must be addressed: (i) understanding oxidation of the YHx films, establishing the link between transparency in the clear state, colorfulness, and kinetics of color change as a function of concentration of O and H; (ii) Interaction
with gases and synthesis of hybrid films, stability with respect to thermal processing, UV light, and humidity; (iii)synthesis through chemical methods. Dissemination, high impact publication, business opportunities and training of young researchers is also expected. The later will deliver a good balance between young and experienced scientists and and assist in achievement of the gender balance. It is multidisciplinary and combines complementary expertise of participants through national and international collaboration. The network has state-of-the-art infrastructure, strong expertise on the topic, and trained manpower to do the work.