Katjonstörning i kvartära kalkogenid-halvledare: kvantifiering, kontroll och konsekvenser
Tidsperiod: 2013-01-01 till 2016-12-31
Projektledare: Jonathan Scragg
Budget: 3 200 000 SEK
The Quaternary Chalcogenides are a group of semiconductors with huge potential in solid-state devices (an example being Cu2ZnSnS4, in development for solar cells). However, there is still a clear need for basic research into the materials. Calculations predict that cation disorder, where atoms occupy the wrong positions in the crystal structure, occurs readily in these materials, and that it strongly affects their properties. However, this disorder is difficult to detect experimentally, and little is known about it. The first aim of this project is therefore to develop tools to quantify disorder in synthesized powders and device-relevant thin films, for which we will use neutron and anomalous X-ray diffraction, as well as looking for traces of disorder in more common measurement techniques. The next aim is to derive kinetic and thermodynamic models of the order-disorder transition from time-resolved annealing data, to enable control of disorder during synthesis. The final aim is to investigate the consequences of disorder for opto-electronic material properties, using electroreflectance and defect spectroscopy. Supported by a strong research group, this challenging project will develop a much-needed area of research. We will gain a deep understanding of the large and interesting family of quaternary chalcogenides, helping them fulfill their promise in advanced device concepts, and contributing to the materials science of higher multinary compounds.