Defect-associated adsorption of monoethanolamine on TiO₂(110): An alternative way to control the work function of oxide electrode

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Controlling defects is one of the basic strategies for tailoring electronic structure of materials, which has not been explored that much yet for organic-inorganic hybrid systems. In this study, we investigated the control of work function of oxide electrode by defect-associated adsorption of molecules at the single-molecule level by means of scanning tunneling microscopy and first principle calculations. The equilibrium adsorption configuration of monoethanolamine (MEA, HO(CH<SUB>2</SUB>)<SUB>2</SUB>NH<SUB>2</SUB>), an effective coating for lowering the work function of an oxide electrode, varies as a function of surface coverage at TiO<SUB>2</SUB>(110) surfaces. Our results showed that defects at the oxide surface and intermolecular interactions dominate the stable configuration of adsorbates as well as work function of the system. The dissociative adsorption at <SUB> O v </SUB> was found to be more efficient at lowering the work function of TiO<SUB>2</SUB>(110) surface, suggesting that defect control can be used to improve the performance of organic-inorganic hybrid systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Both defect and adsorbates at surface modify the work function of the oxide substrate. </LI> <LI> MEA molecules adsorb at oxygen vacancy on TiO<SUB>2</SUB>(110) surface in a dissociated form. </LI> <LI> On perfect TiO<SUB>2</SUB>(110) surfaces, MEA molecules adsorb at Ti rows. </LI> <LI> The largest reduction in work function can be achieved by dissociative adsorption of MEA at oxygen vacancy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The use of well-controlled defects provides an alternative approach to better performance of hybrid organic-inorganic devices.</P> <P>[DISPLAY OMISSION]</P>