title: Enhanced surface-and-interface coupling in Pd-nanoparticle-coated LaAlO3/SrTiO3 heterostructures: strong gas- and photo-induced conductance modulation.
abstract: Pd nanoparticle (NP) coated LaAlO3/SrTiO3 (LAO/STO) heterointerface exhibits more notable conductance (G) change while varying the ambient gas (N2, H2/N2, and O2) and illuminating with UV light (wavelength: 365 nm) than a sample without the NPs. Simultaneous Kelvin probe force microscopy and transport measurements reveal close relationships between the surface work function (W) and G of the samples. Quantitative analyses suggest that a surface adsorption/desorption-mediated reaction and redox, resulting in a band-alignment modification and charge-transfer, could explain the gas- and photo-induced conductance modulation at the LAO/STO interface. Such surface-and-interface coupling enhanced by catalytic Pd NPs is a unique feature, quite distinct from conventional semiconductor hetero-junctions, which enables the significant conductance tunability at ultrathin oxide heterointerfaces by external stimuli.
authors.affiliation: 1] Department of Physics, Ewha Womans University, Seoul 120-750, Korea [2] Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea.
authors.forename: Haeri
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China.
authors.forename: Ngai Yui
authors.initials: NY
authors.lastname: Chan
authors.affiliation: Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China.
authors.forename: Ji-yan
authors.initials: JY
authors.lastname: Dai
authors.affiliation: Department of Physics, Ewha Womans University, Seoul 120-750, Korea.
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Kim