Event details
This talk will be divided into two segments:
The details of the talk and speakers are as follows:
Talk 1 (12-12:25pm)
Title: Application of Laser Processing for Controlling IV Group Semiconductors Properties: Si, Ge, SiGe, GeSn
Speaker: Dr Pavels Onufrijevs (Riga Technical University)
Abstract:
Lasers are highly versatile in semiconductor processing and have a wide range of applications. A new approach is proposed – to use a temperature gradient field induced by powerful pulsed laser radiation with the aim to generate and redistribute point defects and impurity atoms. In this case, there is a possibility to form a graded bandgap structure, form nano-cones, homo- and hetero-junction. The most recent topic of investigation is related to overcoming the equilibrium solubility of Sn atoms in Ge and the relaxation of residual strain in GeSn epitaxial layers by laser radiation. These results could be interesting for the formation of direct bandgap GeSn layers for the construction of IR photodiodes with controlled absorption spectra.
Talk 2 (12:25-12:50pm)
Title: Application of Laser Processing for Controlling Material Properties: Tin Sulphides and Titanium
Speaker: Dr Liga Grase (Riga Technical University)
Abstract:
Laser-induced changes in morphology and phase composition of tin sulphides and titanium allow us to obtain structures with enhanced properties. In the first case, tin disulphide thin films, obtained by close-spaced sublimation method, were irradiated by Nd:YAG laser in order to obtain a layer of tin monosulphide. Furthermore, irradiation of tin monosulphide leads to the formation of a layer of metallic Sn. By considering that n-SnS2 and p-SnS possessed different types of conductivity, this method could be used to obtain solar cells with metallic Sn contact. In the second case, titanium plates were irradiated by femtosecond laser in order to obtain laser-induced periodic surface structures (LIPSS) as well as change the chemical composition of the surface layer. Such structure showed enhanced antibacterial properties against S.aureus and E.coli bacteria in comparison with untreated Ti plates.