Static and Ultrafast Dynamics of Defects of SrTiO3 in LaAlO3/SrTiO3 Heterostructures

A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is attributed to the presence of dominating oxygen defects in SrTiO3 substrate. Using femtosecond laser spectroscopy, the t...

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Bibliographic Details
Published in:arXiv.org 2014-11
Main Authors: X Renshaw Wang, Chen, J Q, A Roy Barman, Dhar, S, Q -H Xu, Venkatesan, T, Ariando
Format: Article
Language:English
Subjects:
Conduction bands
Defects
Energy levels
Heterostructures
Partial pressure
Strontium titanates
Substrates
Online Access:Get full text
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Summary:A detailed defect energy level map was investigated for heterostructures of 26 unit cells of LaAlO3 on SrTiO3 prepared at a low oxygen partial pressure of 10-6 mbar. The origin is attributed to the presence of dominating oxygen defects in SrTiO3 substrate. Using femtosecond laser spectroscopy, the transient absorption and relaxation times for various transitions were determined. An ultrafast relaxation process of 2-3 picosecond from the conduction band to the closest defect level and a slower process of 70-92 picosecond from conduction band to intra-band defect level were observed. The results are discussed on the basis of propose defect-band diagram.
ISSN:2331-8422
DOI:10.48550/arxiv.1411.0551