title: Subnanometer-thick PbS film on organic substrate and its usage as buffer for homo- and heteroepitaxial overgrowth.
abstract: We report on the fabrication of a subnanometer-thick epitaxial PbS film on polydiacetylene (PDA) substrate. The film is formed by cation-absorption in PbCl2 solution followed by sulfidation in mixed H2S/N2 gas, exhibiting a flat and smooth surface morphology. The strong adsorbate-surface interaction between the lead hydrolysis complexes and the carboxyl headgroups on the surface of PDA accounts for such a growth mode. We further demonstrate that such an ultrathin film can be used as a buffer layer for both homo- and heteroepitaxial growth of sulfide films. The X-ray and electron diffraction results reveal that the (001) planes of PbS are parallel to the surface of PDA and the (110) planes of PbS are parallel to the (110) planes of PDA.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Zhang
authors.forename: Shu-Xin
authors.initials: SX
authors.lastname: Hu
authors.forename: Bing
authors.initials: B
authors.lastname: Yuan
authors.forename: Xi-Miao
authors.initials: XM
authors.lastname: Hou
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.forename: Ming
authors.initials: M
authors.lastname: Li