Title: Substantial optical dielectric enhancement by volume compression in ${\mathrm{LiAsSe}}_2$

Abstract

Based on first-principles calculations, we predict a substantial increase in the optical dielectric function of LiAsSe$$_2$$ under pressure. We find that the optical dielectric constant is enhanced threefold under volume compression. This enhancement is mainly due to the dimerization strength reduction of the one-dimensional (1D) As--Se chains in LiAsSe$$_2$$, which significantly alters the wavefunction phase mismatch between two neighboring chains and changes the transition intensity. By developing a tight-binding model of the interacting 1D chains, the essential features of the low-energy electronic structure of LiAsSe$$_2$$ are captured. In conclusion, our findings are important for understanding the fundamental physics of LiAsSe$$_2$$ and provide a feasible way to enhance the material optical response that can be applied to light harvesting for energy applications.

Authors:

Zheng, Fan ^[1]; Brehm, John A. ^[1]; Young, Steve M. ^[2]; Kim, Youngkuk ^[1]; Rappe, Andrew M. ^[1]

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+ Show Author Affiliations

1. Univ. of Pennsylvania, Philadelphia, PA (United States)
2. Naval Research Lab., Washington, D.C. (United States)

Publication Date:

Sun May 15 00:00:00 EDT 2016

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1418314

Alternate Identifier(s):

OSTI ID: 1254075

Grant/Contract Number:  

AC02-05CH11231; FG02-07ER46431

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review B

Additional Journal Information:

Journal Volume: 93; Journal Issue: 19; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE