Preparation and characterization of transparent nanocrystalline TiO2 films posse

2020-04-02 18:12:16

optical absorption films nanocrystalline dependent

责任者: Doherty, S;Fitzmaurice, D 单位: 来源出处: JOURNAL OF PHYSICAL CHEMISTRY, v 100, JUN 20 1996, p 10732- 10738 摘要: We describe the preparation, characterization, and potential-dependent optical absorption spectroscopy of transparent nanocrystalline TiO2 films possessing well-defined morphologies. Regarding preparation, Langmuir-Blodgett techniques are used to deposit between one and four monolayers of TiO2 nanocrystallites on conducting glass. As the average spacing between the nanocrystallites constituting a deposited monolayer may be controlled, the degree of nanoporosity of the resulting nanocrystalline film can be determined. Subsequent firing fuses the constituent crystallites of the deposited monolayers and ensures an ohmic contact with the conducting substrate. Characterization by electron microscopy and optical absorption spectroscopy has been undertaken. The former reveals the above films to be nanoporous or close-packed arrays of anatase nanocrystallites. The latter has allowed determination of an absorption coefficient for anatase at 326 nm. Measurement of potential-dependent optical absorption spectra has also proved possible. Results obtained suggest that the degree of charge accumulation possible at a given applied potential is dependent on the morphology of the nanocrystalline film. 关键词: nanostructures; electronic states; optical properties; CONDUCTION-BAND ELECTRONS; OXIDE SEMICONDUCTOR ELECTRODE; ANODIC OXIDATIVE HYDROLYSIS; OPTICAL ELECTROCHEMISTRY; POLYCRYSTALLINE TIO2; OXIDATIVE HYDROLYSIS; OPTICAL ELECTROCHEMISTRY; POLYCRYSTALLINE TIO2; SPECTROSCOPIC DETERMINATION; CHARGE SEPARATION; ZNO FILMS; SPECTROSCOPIC DETERMINATION; CHARGE SEPARATION; ZNO FILMS; PHOTOELECTROCHEMISTRY; LIGHT PHOTOELECTROCHEMISTRY; LIGHT