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Graphene/Strontium Titanate: Approaching Single Crystal–Like Charge Transport in Polycrystalline Oxide Perovskite Nanocomposites through Grain Boundary Engineering
Author(s) -
Lin Yue,
Dylla Maxwell Thomas,
Kuo Jimmy Jiahong,
Male James Patrick,
Kinloch Ian Anthony,
Freer Robert,
Snyder Gerald Jeffery
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201910079
Subject(s) - materials science , strontium titanate , graphene , grain boundary , crystallite , oxide , perovskite (structure) , charge carrier , nanocomposite , condensed matter physics , thermoelectric effect , crystal (programming language) , nanotechnology , microstructure , chemical physics , composite material , chemical engineering , thin film , optoelectronics , metallurgy , thermodynamics , physics , computer science , engineering , programming language
Grain boundaries critically limit the electronic performance of oxide perovskites. These interfaces lower the carrier mobilities of polycrystalline materials by several orders of magnitude compared to single crystals. Despite extensive effort, improving the mobility of polycrystalline materials (to meet the performance of single crystals) is still a severe challenge. In this work, the grain boundary effect is eliminated in perovskite strontium titanate (STO) by incorporating graphene into the polycrystalline microstructure. An effective mass model provides strong evidence that polycrystalline graphene/strontium titanate (G/STO) nanocomposites approach single crystal‐like charge transport. This phenomenological model reduces the complexity of analyzing charge transport properties so that a quantitative comparison can be made between the nanocomposites and STO single crystals. In other related works, graphene composites also optimize the thermal transport properties of thermoelectric materials. Therefore, decorating grain boundaries with graphene appears to be a robust strategy to achieve “phonon glass–electron crystal” behavior in oxide perovskites.