Surface Science and Optical Spectroscopy Studies of Oligothiophene Adsorption on Clean and Oxygen-Dosed Aluminum Surfaces

清洁和掺氧铝表面上低聚噻吩吸附的表面科学和光谱研究

• 批准号: 0089960
• 负责人: James Whitten
• 金额: $ 29.19万
• 依托单位: University of Massachusetts Lowell Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0089960&HistoricalAwards=false
• 关键词: Surface; Science; Optical; Spectroscopy; Studies

The aim of this project is to investigate the adsorption of thiophene oligomers on well-characterized aluminum surfaces are proposed. X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) studies at a variety of temperatures will be performed to examine the organic layer/aluminum interface formed by exposing clean, single crystal and polycrystalline aluminum surfaces to gas phase, vacuum-sublimed, or x-ray-formed oligothiophenes. XPS will provide information regarding chemistry that is occurring at the interface, and UPS will be used to determine the electronic valence structure of the metal and how it changes upon oligothiophene adsorption. These results will be correlated with work function and optical spectroscopy measurements. Adsorption of a variety of substituted thiophene oligomers will also be studied at different temperatures on single crystals of aluminum, and low energy electron diffraction (LEED) and photoluminescence will be performed to search for evidence of oligomer ordering. Surface photovoltaic spectroscopy measurements will also be carried out to investigate changes in the position of the Fermi level that occur upon absorption of light. Oligothiophene coadsorption on oxygen-dosed aluminum surfaces and on aluminum oxide will also be investigated to determine how adsorption on these surfaces differs from on clan aluminum. Weaker chemical interaction is expected on the oxygen-expose surfaces, and possibilities should exist for oligothiophene alignment. Thermal desorption spectroscopy and LEED will be used to assess adsorption/desorption behavior and ordering of the adsorbed oligomers.%%%Aluminum is commonly used as an electrode material for polymeric light-emitting diodes (LEDs), field-effect transistors and photovoltaics, and substituted thiophenes are an important class of polymers for these types of devices. Device materials are of significant importance to industry, and students trained in these areas compete well in the job market. This project is being jointly supported by The Solid-State Chemistry Program in The Division of Materials Research and The Advance Materials and Processing Program in the Chemistry Division.

本项目的目的是研究噻吩低聚物在表征良好的铝表面的吸附。将在不同温度下进行x射线和紫外光电子能谱（XPS和UPS）研究，以检查通过将清洁的单晶和多晶铝表面暴露于气相，真空升华或x射线形成的寡硫吩形成的有机层/铝界面。XPS将提供有关界面上发生的化学反应的信息，UPS将用于确定金属的电子价结构以及它在寡硫吩吸附后的变化。这些结果将与功函数和光谱学测量相关联。本文还将研究不同温度下各种取代噻吩低聚物在铝单晶上的吸附，并利用低能电子衍射（LEED）和光致发光等方法寻找低聚物有序的证据。表面光伏光谱测量也将进行，以研究费米能级位置的变化，发生在光的吸收。还将研究寡硫吩在含氧铝表面和氧化铝表面的共吸附，以确定在这些表面上的吸附与在族铝表面上的吸附有何不同。预计在氧暴露表面上的化学相互作用较弱，并且应该存在低聚噻吩排列的可能性。热解吸光谱和LEED将用于评估吸附/解吸行为和吸附低聚物的顺序。铝通常用作聚合物发光二极管（led）、场效应晶体管和光伏电池的电极材料，而取代噻吩是这些类型器件中重要的一类聚合物。器件材料对工业具有重要意义，在这些领域受过训练的学生在就业市场上具有很强的竞争力。本项目由材料研究部固态化学项目和化学部先进材料与加工项目联合支持。