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Colloquium: Prof. James P. Lewis, WVU

Location

Physics : 401

Date & Time

October 22, 2014, 3:30 pm4:30 pm

Description

TITLE:   High-throughput computational design of photo-active materials

ABSTRACT: The discovery of new materials is critical for improving industries aimed at addressing challenges in clean energy, national security, and human welfare. However, it can take up to 20 years for a newly discovered material to be used in an applications. Under the Materials Genome Initiative, the pace of discovery and deployment of advanced material systems will accelerate. Modeling materials properties of large composite systems is an interesting challenge as materials research grows directed more towards non-homogeneous composite systems (e.g. molecules on a semiconductor interface). Our computational approach, called FIREBALL which is based on density-functional theory, addresses this challenge in a unique manner so that computational materials searching is a truly high-throughput approach utilizing computational resources efficiently. We are pursuing one particular challenging research direction, that is, to find more optimal photocatalysts (materials which utilize the sun’s energy to catalyze chemical reactions). The critical aspect of this challenge is searching for materials that are stable in chemical environments as well as opto-electronically active in the visible. Recently, we have been investigating a class of oxide materials called delafossites. In these materials, there is an intriguing property of a forbidden optical transition (Laporte selection rule), which is prototypical of many delafossite systems, yielding transparent, but conducting materials. Delafossite oxides are of the form ABO2, hence alloying at the A or B site will yield an alloyed material with enhanced photo-absorption resulting from symmetry breaking. We will present results of AB11-xB2xO2 alloys (with A = Cu, B1 = Al, Ga, In, and B2 = Fe) using high-throughput calculations and data mining techniques, we show the most likely positional configurations for x = 0.00 through x = 0.10 of the B2-site atoms relative to one another. Implications of this result and applications of the techniques used are discussed, including the development of candidate materials via high-throughput analysis of constituent search-space. We will discuss the optical properties of optimal (energetically) delafossite oxide candidates.

Location: Physics, Room 401