Spatial density profile of electrons near the LaAlO3/SrTiO3 heterointerface revealed by time-resolved photoluminescence spectroscopy
Abstract
The depth profile of the electron density near the LaAlO3/SrTiO3 heterointerface has been studied by means of time-resolved photoluminescence (PL) spectroscopy. A broad blue PL band is observed at 2.9 eV, originating from the two-carrier radiative recombination of interface-induced electrons and photoexcited holes. The PL lifetime of LaAlO3/SrTiO3 heterointerface is dominated by the three-carrier Auger recombination of electrons and holes and is sensitive to electron density. We tuned the probing depth by changing the excitation photon energy and evaluated the carrier-density profile using the relation between the carrier density and the PL lifetime. Our non-contact probe method based on PL spectroscopy indicates that the carriers are confined within several nanometers in depth near the LaAlO3/SrTiO3 heterostructures.
- Publication:
-
Applied Physics Letters
- Pub Date:
- April 2014
- DOI:
- 10.1063/1.4872171
- Bibcode:
- 2014ApPhL.104o1907Y