Since its development in early 2000鈥檚, the High-Throughput evaporative Physical Vapour Deposition (HT-ePVD) methodology has been used to tackle various material innovations. The technology was key to the creation of Ilika Technologies Ltd, then a spinout company from the School of Chemistry specialising in material innovations using our high throughput approach with a focus on the metallurgy, electronics and energy sectors. During the last 20 years research projects led by both the Advanced Composite Materials Facility (now Material Innovation Laboratory) at the School of Chemistry, and Ilika have allowed further developments and specialisation in many aspects of material research as well as high-throughput technologies.
The relies on simple geometry to allow intimate atomic mixing of elements. Each evaporated element has its own thermal evaporator (either an effusion cell or an electron beam source) and the concept uses the broad source nature of the evaporating material to create a shadowing of each source and achieve a variation in the deposition rate of each element as a function of position on the substrate. The high purity evaporants used in the ultra high vacuum environment produce high quality thin films which enabled the synthesis and optical characterisation of . The co-deposition of all the constituents creates unique libraries and offers deep insight into the structure-composition-property relationship:
A benefit of the control of the composition spread of our technique is the fixed size of each library (35x35 mm2). This enables the design and use of functional substrates such as Microelectromechanical Systems (MEMS). The simplest and probably most versatile is the Electrochemical Array which enables parallel electrochemical screening of 100 different compositions. It has been successfully employed to synthesise and screen alloys used for:
Another innovative and versatile MEMS device is an array of 49 micro-hotplates used for where the characteristics of hydrogen absorption were probed as a function of composition. A modified version of the hot-plate array enabled the development of screening methodology for looking at . The ability to capture single images of an entire library has, early on, showed the power of the high-throughput approach, this was further explored when focusing on the .
Each deposition chamber can hold up to 6 elemental sources, which can used simultaneously for the synthesis of multicomponent alloys. As well as binaries, ternaries, quaternaries, quinaries and senaries systems can be synthesised and characterised. This has facilitated projects in metallurgy and advanced alloys, such as:
The use of radio frequency (RF) atom sources to generate highly reactive fluxes of atomic gases (atomic oxygen, nitrogen or hydrogen) mixing directly with the condensed co-evaporants on the substrates have led to direct synthesis of complex materials, such as:
Combining many of these aspects, we can even probe functional thin film structure as in the case of . Many other aspects of material research can be assessed using our high-throughput approach, including passive dielectrics, thermoelectrics, photovoltaics and gas sensors.
