Manufacture of indium-free, transparent and conductive layers in a high rate process
The Fraunhofer FEP has further developed the deposition of niobium-doped titanium dioxide layers to make it a cost-efficient process suitable for industrial use. As a result of this, large glass surfaces can be upgraded towards durable, highly-tailored glasses in a stable and reproducible process.
The need for new, improved and sustainable materials which are available in large quantities is becoming ever more important in all branches of the high-tech sector. Indium is a raw material that is becoming more expensive all the time.
Large-area transparent conductive electrodes from Fraunhofer FEP
It has however played a key role in the manufacture of transparent conductive oxides (TCO) used in touch screens, solar cells and electronic displays. It is for this reason that the development of transparent conductive materials which are indium-free is such an important step towards sustainable products.
The Fraunhofer Institute for Electron Beam and Plasma Technology FEP is pioneer in the development of large-area deposition of niobium-doped titanium dioxide layers as an alternative to traditional transparent conductive electrodes containing indium. Titanium dioxide, which is also to be found in opaque white and toothpaste, is in contrast to indium available in abundant quantities and is already subject to widespread and wide-ranging use in the optics industry as a highly refractive material.
As one of the first institutes worldwide, Fraunhofer FEP can procure niobium-doped titanium dioxide layers in a highly efficient magnetron sputtering process which is suitable for application in the industrial sector. Fraunhofer FEP has achieved this in an in-line vacuum system with a coating rate of 55 nm ∙ m/min (at a power input of 16 kW/m). The decisive step which was made in order to achieve this very good deposition rate, and as a result, a manufacturing process which could be implemented on an industrial level, was from the original deposition using planar magnetrons through to the deposition using an oxidized rotatable target.
With a resistivity of 8.7 ∙ 10-4 Ω ∙ cm, the layers have shown themselves to have similar conductive properties and with an extinction coefficient of 0.014 (at a wavelength of 550 nm) to be similarly transparent as other TCO materials, but with a particular resistance to chemicals and climatic and environmental influences. This could be clearly seen after 300 days (from March to January) of exposure to different weather conditions, the layers did not degrade and still remained sufficiently electrically conductive. As a result of their physical resilience, the layers are particularly suitable for use as transparent conductive protective layers for outdoor applications, for example in the automotive or architectural sectors.
Dr. Manuela Junghähnel, Senior Scientist at Fraunhofer FEP, will show at the Glass Performance Days in Tampere / Finland the titanium dioxide layers and the new glass refinement process. Her presentation on the 13th of June 2013 is entitled “Advanced, cost effective and sustainable low-emittance coatings based on titania for improved long wave radiation reflection in window applications”.
More information about the „Glass Performance Days“ can be found under:
Annett Arnold, M.Sc.
Fraunhofer-Institut für Elektronenstrahl- und Plasmatechnik FEP
Phone +49 351 2586-452
Winterbergstraße 28 | 01277 Dresden | Gemany |
Annett Arnold | Fraunhofer-Institut
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
Nano-hologram paves way for integration of 3-D holography into everyday electronics
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...