Electronic Band Alignment at Complex Oxide Interfaces Measured by Scanning Photocurrent Microscopy.

ABSTRACT: The band alignment at an Al₂O₃/SrTiO₃ heterointerface forming a two-dimensional electron gas (2DEG) was investigated using scanning photocurrent microscopy (SPCM) in an electrolyte-gated environment. We used a focused UV laser source for above-the-bandgap illumination on the SrTiO₃ layer, creating electron-hole pairs that contributed to the photocurrent through migration towards the metal electrodes. The polarity of the SPCM signals of a bare SrTiO₃ device shows typical p-type behavior at zero gate bias, in which the photogenerated electrons are collected by the electrodes. In contrast, the SPCM polarity of 2DEG device indicates that the hole carriers were collected by the metal electrodes. Careful transport measurements revealed that

SUBMITTER: Yoon JH 

PROVIDER: S-EPMC5476647 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature