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Band Alignment at Heteroepitaxial Perovskite Oxide Interfaces. Experiments, Methods, and Perspectives
Author(s) -
Giampietri Alessio,
Drera Giovanni,
Sangaletti Luigi
Publication year - 2017
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201700144
Subject(s) - heterojunction , materials science , photovoltaics , band diagram , band gap , perovskite (structure) , optoelectronics , x ray photoelectron spectroscopy , oxide , photoemission spectroscopy , thin film , nanotechnology , epitaxy , engineering physics , photovoltaic system , electrical engineering , chemistry , chemical engineering , physics , crystallography , layer (electronics) , metallurgy , engineering
Recent advances in the growth of epitaxial oxide thin films have fostered a steady increase of research on perovskite oxide heterojunctions, which are now produced with unprecedented quality. Applications of these ultra‐thin interfaces in the field of electronics, photon harvesting, photovoltaics and photocatalysis strongly rely on the capability to master band gap engineering at the nanoscale. In this report the band gap alignment at all‐oxide perovskite interfaces is reviewed, with focus on oxide perovskite layers grown on SrTiO 3 , as these systems can display a two dimensional electron gas at the interface, disclosing possible applications in the next‐generation nanoelectronic devices. Papers reporting an experimental determination of band diagram are considered. The most reliable methods to experimentally track the band alignment at the interface are presented, based on photoelectron spectroscopy analysis of core level or valence band structures, including recent resonant photoemission spectroscopy studies. Experimental data from several conducting and insulating SrTiO 3 ‐based heterostructures are presented and results are discussed through comparison with theoretical predictions. It is shown that electron spectroscopies are a powerful tool to investigate band alignment and to address band engineering issues, filling the gap between theoretical predictions and a relatively limited experimental dataset.