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Communication: The electronic entropy of charged defect formation and its impact on thermochemical redox cycles

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.5022176· OSTI ID:1424583
 [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
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The ideal material for solar thermochemical water splitting, which has yet to be discovered, must satisfy stringent conditions for the free energy of reduction, including, in particular, a sufficiently large positive contribution from the solid-state entropy. By inverting the commonly used relationship between defect formation energy and defect concentration, it is shown here that charged defect formation causes a large electronic entropy contribution manifesting itself as the temperature dependence of the Fermi level. This result is a general feature of charged defect formation and motivates new materials design principles for solar thermochemical hydrogen production.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States); Energy Frontier Research Centers (EFRC) (United States). Center for Next Generation of Materials by Design: Incorporating Metastability (CNGMD)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Hydrogen and Fuel Cell Technologies Program (EE-3F); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1424583
Report Number(s):
NREL/JA--5K00-70968
Journal Information:
Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 7 Vol. 148; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (25)

Considerations in the Design of Materials for Solar-Driven Fuel Production Using Metal-Oxide Thermochemical Cycles journal October 2013
A thermodynamic study of nonstoichiometric cerium dioxide journal November 1975
Advances and trends in redox materials for solar thermochemical fuel production journal November 2017
Effect of isotopic mass on the photoluminescence spectra of zinc oxide journal October 2003
High-Throughput Computational Screening of Perovskites for Thermochemical Water Splitting Applications journal July 2016
Factors Affecting the Efficiency of Solar Driven Metal Oxide Thermochemical Cycles journal February 2013
Giant onsite electronic entropy enhances the performance of ceria for water splitting journal August 2017
Oxide enthalpy of formation and band gap energy as accurate descriptors of oxygen vacancy formation energetics journal January 2014
Practical doping principles journal July 2003
Semiconducting transition metal oxides journal June 2015
Pressure dependence of deep levels in GaAs journal June 1982
Native defects and self-compensation in ZnSe journal May 1992
Anion vacancies as a source of persistent photoconductivity in II-VI and chalcopyrite semiconductors journal July 2005
Hybrid functionals applied to rare-earth oxides: The example of ceria journal January 2007
First-principles calculations of the temperature dependence of the band gap of Si nanocrystals journal October 2007
First-principles thermodynamic framework for the evaluation of thermochemical H 2 O - or CO 2 -splitting materials journal December 2009
Ab initio thermodynamics of intrinsic oxygen vacancies in ceria journal October 2012
Convergence of density and hybrid functional defect calculations for compound semiconductors journal September 2013
Implications of the band gap problem on oxidation and hydration in acceptor-doped barium zirconate journal June 2015
Disentangling the role of small polarons and oxygen vacancies in Ce O 2 journal June 2017
Chemical potential dependence of defect formation energies in GaAs: Application to Ga self-diffusion journal October 1991
Magnetism without Magnetic Ions: Percolation, Exchange, and Formation Energies of Magnetism-Promoting Intrinsic Defects in CaO journal March 2006
Dopability, Intrinsic Conductivity, and Nonstoichiometry of Transparent Conducting Oxides journal January 2007
Implications of the band gap problem on oxidation and hydration in acceptor-doped barium zirconate text January 2015
Anion vacancies as a source of persistent photoconductivity in II-VI and chalcopyrite semiconductors text January 2005

Cited By (4)

Computational Fermi level engineering and doping-type conversion of Ga2O3 via three-step synthesis process text January 2021
Interplay between Composition, Electronic Structure, Disorder, and Doping due to Dual Sublattice Mixing in Nonequilibrium Synthesis of ZnSnN 2 :O journal January 2019
BaCe 0.25 Mn 0.75 O 3−δ —a promising perovskite-type oxide for solar thermochemical hydrogen production journal January 2018
Defect phase diagram for doping of Ga 2 O 3 journal April 2018

Figures / Tables (2)

Figure 1(p. 2)figure Figure 1
Figure 2(p. 4)figure Figure 2

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Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
defect equilibria
redox cycles
solar thermochemical
water splitting