The next ISSP UL / Doctoral school "Functional materials and nanotechnologies" scientific workshop will take place on May 18, 13:00.

Two lectures will be given by Associate prof. Wei Cao (University of Oulu).

The titles of the lectures are "Biomimetic antireflection design: surface engineering and physics beyond" and "Synchrotron-radiation-based studies of advanced steels: inclusions and phase transformation ".

Biomimetic antireflection design: surface engineering and physics beyond

Nature endows human with infinite number of prototypes for biomimicry. Foliage, the primary medium where photosynthesis happens, is a typical master deserving careful investigations especially in solar energy aspects due to its key functionality of light harvesting. This talk is dedicated to introducing antireflective designs learnt from surface structures of the foliage and the applications to enhance efficiency of solar cells. The surface reflectivity was substantially decreased after placing the leaf-mimicked antireflective foils on to Si-based solar cells. As a result, up to an additional 17% gain can be reached. The antireflective mechanism of leaf structures was elucidated, and the diffusion-coupling was found as the main reason of the enhanced light harvesting efficiency. Thanks to the mechanistic driven study, a facile antireflection design route was established with the natural spices as the biomimicry master.

Synchrotron-radiation-based studies of advanced steels: inclusions and phase transformation

Steel, while being the most widely used and irreplaceable engineering material, challenges human’s understanding of its processing down at quantum mechanical level. It has embedded detrimental and beneficial inclusions, and moreover, requires balanced phases to reach desired mechanical properties. In this lecture, physical mechanisms of inclusion formations and phase transformations will be explored by using cutting-edge synchrotron-based techniques combined with first-principles calculations. In the first part, we show the tendencies of coexistence of typical inclusions subjected to spectromicroscopic determinations and their formation energies. The second part is to illustrate the in situ and quantitative determinations of phase transformation during quenching and partitioning, and the carbon diffusion paths to induce the transformation. Studies of phases within glasses of slags during steelmaking will also be briefed.

The lectures will be given in English.