Photoconductivity in 2D electron gases at the amorphous-LGO/STO oxide interface: a dynamical analysis

Two-dimensional electron gases (2DEGs) at oxide interfaces still show, almost 15 years after their discovery, new intriguing and unexpected properties. The discovery of 2D electron gases in interfaces with an amorphous overlayer has made the debate about the origin of the free electrons even more intense. Here, it is shown a substantial conductivity modulation induced by light in 2DEG at the amorphous-LaGaO3/SrTiO3. Visible-range photons induce a strongly temperature-dependent conductivity increase. The extensive measurements, ranging from 300 K down to 8 K, with light intensity between 25 and 100 mW/cm2, deepen the understanding of the photo-responsivity dynamics, while correlating it with the electric transport mechanism. The reported data show interesting findings, useful to clarify several aspects of the complex physics of this material.