The Preparation And Characterization Of Conducting Polymer-Semiconductor Nanoparticle Composite Film

The Preparation and Characterization of Conducting Polymer-Semiconductor Nanoparticle Composite Film Though there are many methods for preparation, the semiconductor na-no-material can not be widely used because of its minor size, high surface energy and easy aggregation. If semiconductor nano-material is integrated with polymer, the polymer can act as a carrier to control the size and distribution of particles and to increase the stability. Moreover, the characteristic of particles can be used for material only by compounding and assembling with other bulk materials. The polymer gains an advantage over other materials in compounding and assembling with semiconductor nanoparticles for its well worked ability. The composite film can be widely used as novel nonlinear optical material, electroluminescent material, laser amplifier, and so on. So the interest in the development of conducting polymer-semiconductor nanoparticle composite film has grown exponentially in recent years. In this paper, the p-aniinothiophenol(PATP) film and polyaniline(PANI) film were sequential prepared on the surfaces of different substrates by electrochemical- assembly(ECA). The dynamic process of self-assembling PATP and the surface topography, construction and photo-electrochemical property of PANI were studied. Based on the studies of the stmcture and property of PANI, the T102-PANI, ZnO-PANI and CdS-PANI composite films were prepared by the ECA-electrodeposition and ECA sollgel combined techniques. The structure, topography and property of these composite film were also studied. The experimental techniques used in this work include atomic force spectroscopy(AFM), scanning tunneling microscopy(STM), scanning electronic microscopy(SEM), Raman scattering spectroscopy (SERS), fluorescence spectroscopy, photocurrent spectroscopy, X-ray photoelectron spectroscopy (XPS), electrochemical quartz crystal microbalance (EQCM), cyclic voltammetry (CV), etc. Moreover, the PANL nanotubes, ZnO nanowires and ZnO-PANI coaxial nanowires and their arrays were synthesized using anodic aluminum oxide(AAO) membrance. The topography and property of them were also studied. The main results from those studies are sun-imarized as following: 1. The ordered PATP monolayer was obtained on the Au substrate by self- assembly: (1) The process of the self-assembly of PATP includes adsorption step and restructuring step. (2) PATP molecules adsorb on Au with standing mode through S-Au bond. (3) The assembling of PATP favors the polymerization of aniline and affects the structure and topography of PANI. 2. The conducting PANI was obtained on the PATP monolayer by ECA: (1) Three redox state PAM with porous and flocculent structure were prepared, and their electron transfer and photo-electrochemical properties were also studied. (2) The Fowler plots obtained from photocurrent spectra of partially-oxidized PANT show that PANI has the internal photoemission effect. The bandgap energy of insulating matrix in partially-oxidized PANT is determined as 3.33 eV by the Fowler plots. The flat-band potentials of partially-oxidized PANT and reduced PANT, in the The Preparation and Characterization of Conducting Polymer-Semiconductor Nanopeit~cle Composite Film order of 0.63 V vs. SCE, were obtained from Mott-Schottky plots. The energy band scheme of partially-oxidized PANT was also gained. (3) A novel model on photoelectrochemical process based on internal photoemission of partially-oxidiz...