Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures
Cation stoichiometry has been identified as a major key in establishing 2-dimensional electron gases (2DEGs) in oxide heterostructures. Here, we discuss a 2DEG formation scenario in B-site deficient perovskite/perovskite heterostructures, which previously were predicted to show insulating behavior....
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
AIP Publishing LLC
2018-07-01
|
| Series: | APL Materials |
| Online Access: | http://dx.doi.org/10.1063/1.5038773 |
| _version_ | 1828749253051154432 |
|---|---|
| author | F. Gunkel C. Lenser C. Baeumer F. Borgatti F. Offi G. Panaccione R. Dittmann |
| author_facet | F. Gunkel C. Lenser C. Baeumer F. Borgatti F. Offi G. Panaccione R. Dittmann |
| author_sort | F. Gunkel |
| collection | DOAJ |
| description | Cation stoichiometry has been identified as a major key in establishing 2-dimensional electron gases (2DEGs) in oxide heterostructures. Here, we discuss a 2DEG formation scenario in B-site deficient perovskite/perovskite heterostructures, which previously were predicted to show insulating behavior. We elaborate an ionic picture based on oxygen-vacancy-buffered B-site vacancy defects in the polar oxide layer that yields a continuous transition from 2DEG formation to less conducting interfaces to insulating interfaces with increasing B-site deficiency. Experimentally, a corresponding modulation of charge transfer across NdGaO3/SrTiO3 interfaces is inferred using hard x-ray photoelectron spectroscopy analysis and transport experiments. With increasing B-site deficiency, we observe a decrease of the interfacial Ti3+ core level contribution, indicating a reduced charge transfer at the interface. This result is corroborated by temperature-dependent transport measurements, revealing increased low temperature resistance, with a dominant influence of a reduced electron density in the Ga-depleted sample. We consider a redistribution of oxygen vacancies in the B-site deficient polar oxide layer to explain the alleviated interface reconstruction, adding a new perspective on potential built-up in polar-oxide thin films. |
| first_indexed | 2024-12-10T14:27:29Z |
| format | Article |
| id | doaj.art-b9cadf086811410b813c7974893b597c |
| institution | Directory Open Access Journal |
| issn | 2166-532X |
| language | English |
| last_indexed | 2024-12-10T14:27:29Z |
| publishDate | 2018-07-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | APL Materials |
| spelling | doaj.art-b9cadf086811410b813c7974893b597c2022-12-22T01:45:03ZengAIP Publishing LLCAPL Materials2166-532X2018-07-0167076104076104-910.1063/1.5038773006807APMCharge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructuresF. Gunkel0C. Lenser1C. Baeumer2F. Borgatti3F. Offi4G. Panaccione5R. Dittmann6Institute of Electronic Materials (IWE2), RWTH Aachen University, Aachen, GermanyIEK-1, Forschungszentrum Jülich, 52425 Jülich, GermanyJülich-Aachen Research Alliance, Fundamentals of Future Information Technology (JARA-FIT), Aachen, GermanyCNR–Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), Via P. Gobetti 101, I-40129 Bologna, ItalyCNISM and Dipartimento di Scienze, Università di Roma Tre, Via della Vasca Navale 84, 00146 Rome, ItalyCNR–Istituto Officina dei Materiali (IOM), Laboratorio TASC, S.S. 14 Km 163.5, AREA Science Park, Basovizza, 34149 Trieste, ItalyJülich-Aachen Research Alliance, Fundamentals of Future Information Technology (JARA-FIT), Aachen, GermanyCation stoichiometry has been identified as a major key in establishing 2-dimensional electron gases (2DEGs) in oxide heterostructures. Here, we discuss a 2DEG formation scenario in B-site deficient perovskite/perovskite heterostructures, which previously were predicted to show insulating behavior. We elaborate an ionic picture based on oxygen-vacancy-buffered B-site vacancy defects in the polar oxide layer that yields a continuous transition from 2DEG formation to less conducting interfaces to insulating interfaces with increasing B-site deficiency. Experimentally, a corresponding modulation of charge transfer across NdGaO3/SrTiO3 interfaces is inferred using hard x-ray photoelectron spectroscopy analysis and transport experiments. With increasing B-site deficiency, we observe a decrease of the interfacial Ti3+ core level contribution, indicating a reduced charge transfer at the interface. This result is corroborated by temperature-dependent transport measurements, revealing increased low temperature resistance, with a dominant influence of a reduced electron density in the Ga-depleted sample. We consider a redistribution of oxygen vacancies in the B-site deficient polar oxide layer to explain the alleviated interface reconstruction, adding a new perspective on potential built-up in polar-oxide thin films.http://dx.doi.org/10.1063/1.5038773 |
| spellingShingle | F. Gunkel C. Lenser C. Baeumer F. Borgatti F. Offi G. Panaccione R. Dittmann Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures APL Materials |
| title | Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures |
| title_full | Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures |
| title_fullStr | Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures |
| title_full_unstemmed | Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures |
| title_short | Charge-transfer in B-site-depleted NdGaO3/SrTiO3 heterostructures |
| title_sort | charge transfer in b site depleted ndgao3 srtio3 heterostructures |
| url | http://dx.doi.org/10.1063/1.5038773 |
| work_keys_str_mv | AT fgunkel chargetransferinbsitedepletedndgao3srtio3heterostructures AT clenser chargetransferinbsitedepletedndgao3srtio3heterostructures AT cbaeumer chargetransferinbsitedepletedndgao3srtio3heterostructures AT fborgatti chargetransferinbsitedepletedndgao3srtio3heterostructures AT foffi chargetransferinbsitedepletedndgao3srtio3heterostructures AT gpanaccione chargetransferinbsitedepletedndgao3srtio3heterostructures AT rdittmann chargetransferinbsitedepletedndgao3srtio3heterostructures |