Proton disorder in cubic ice: Effect on the electronic and optical properties.
The proton disorder in ice has a key role in several properties such as the growth mode, thermodynamical properties, and ferroelectricity. While structural phase transitions from proton disordered to proton ordered ices have been extensively studied, much less is known about their electronic and optical properties. Here, we present ab initio many body perturbation theory-based calculations of the electronic and optical properties of cubic ice at different levels of proton disorder. We compare our results with those from liquid water, that acts as an example of a fully (proton- and oxygen-)disordered system. We find that by increasing the proton disorder, a shrinking of the electronic gap occurs in ice, and it is smallest in the liquid water. Simultaneously, the excitonic binding energy decreases, so that the final optical gaps result to be almost independent on the degree of proton disorder. We explain these findings as an interplay between the local dipolar disorder and the electronic correlation.
MIFP, ETSF, Physics Department of Tor Vergata University, Via della Ricerca Scientifica 1, I-00133 Rome, Italy.
Viviana
V
Garbuio
Department of Chemistry and Centre for Theoretical and Computational Chemistry (CTCC), University of Oslo, Postboks 1033, Blindern, N-0315 Oslo, Norway.
Michele
M
Cascella
MIFP, V. Lashkarev Institute of Semiconductor Physics of National Academy of Sciences of Ukraine, pr. Nauki 45, UA-03680 Kiev, Ukraine.
Igor
I
Kupchak
MIFP, ETSF, Physics Department of Tor Vergata University, Via della Ricerca Scientifica 1, I-00133 Rome, Italy.
Olivia
O
Pulci
Institut für Chemie, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Ari Paavo
AP
Seitsonen