Figure 3: Exploring the mechanism of conductivity switching in LAO/STO heterointerfaces.
From: Giant conductivity switching of LaAlO3/SrTiO3 heterointerfaces governed by surface protonation
(a) R of 4 uc LAO/STO measured before (circles) and after (squares) 1 min of immersion in solvents with varying concentrations of free protons. (b) (Left) Log base 10 of the ratio of the resistance Rf measured following a 2-min immersion in toluene (TOL), tetrahydrofuran (THF), dichloromethane (DCM), acetophenone (ACO), acetaldehyde (ACA), ethanol (EtOH), nitromethane (MeNO2), dimethylformamide (DMF), acetonitrile (MeCN), water (H2O) or formamide (Form) to the resistance in the conductive state Ri. Blue and red markers represent solvents that do and do not function as Lewis bases, respectively. (right) Rf/Ri versus the pKa of the protonated solvents. (c) Ratio of sheet resistance change ΔR to R normalized by the delivered optical energy E following illumination with light of a specified wavelength.
