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11.7 poster.jpg

 

[Lecture 1]

- 연사 : Prof. Rustam Z. Khaliullin / Department of Chemistry, McGill University

- 일시 : 201711월 7(화), 16:00 ~ 17:00

- 장소 : KI 빌딩(E4), Connect Room (2F)

- 주제 : Ab initio molecular dynamics on nanoscale

-  Abstract

Despite remarkable recent progress in linear-scaling density function theory, the computational cost of exist-ing methods remains too high for routine ab initio molecular dynamics (AIMD) simulations. We developed a linear-scaling AIMD method with an extremely low computational overhead by assuming that electrons in materials are strictly localized within predened radii. High eciency of the method is achieved without sacricing its accuracy with a combination of two techniques: (1) on-the-y construction of accurate localized orbitals without lengthy optimization and (2) the stochastic integrator that is ne-tuned to retain stable dynamics even with imperfect forces. A remarkable feature of the implemented method is that it remains ecient for challenging condensed phase systems even if large accurate basis sets are used. We demonstrated that, for systems well-represented by localized electrons (e.g. molecular systems, ionic salts), the new AIMD method enables simulations on previously inaccessible time and length scales. Applications of the method to more challenging

systems of strongly interacting atoms (e.g. covalent crystals) will also be discussed.

 

[Lecture 2] 2017 EEWS Distinguished Lecture

- 연사 : Prof. Aron Walsh / Department of Materials, Imperial College London

- 일시 : 201711월 7(화), 17:00 ~ 18:00

- 장소 : KI 빌딩(E4), Connect Room (2F)

- 주제 : Next - generation materials for solar energy conversion

- Abstract

Solar energy is a clean, abundant, and sustainable energy resource. Since the discovery of the photovoltaic effect in the late 19th century, a large number of materials have been tried and tested for solar energy conversion. However, the majority of commercial devices are based on silicon technologies. The next-generation of thin-film solar cells have the potential to lower the cost of solar electricity and enable building-integrated photovoltaic systems.

The most fundamental factor that determines whether a material can be employed in a photovoltaic or photoelectrochemical device is optical absorption, which should be strong in the visible range of the solar spectrum. In addition, defect physics controls electron and hole concentrations, electronic band alignments influence the efficiency of charge extraction, while thermodynamic stability and chemical processing limit practical synthesis and scale-up.

In this talk, I will present our recent progress in the design and optimisation of new solar energy materials with an emphasis on performance descriptors from materials simulations. Structure-property relationships in the kesterite (e.g. Cu2ZnSnS4) and perovskite (e.g. CsSnI3 and CH3NH3PbI3) families will be discussed, in addition to the matlockite (PbFCl type) and herzenbergite (SnS type) systems. New directions in the field, including the development of defect tolerant semiconductors [5] will also be addressed.

 

* 첨부 : 포스터,

 

[주관] 정유성 교수(내선.1712) / [문의] 이수현(suehyun@kaist.ac.kr, 내선.1752)