Weng Xiaolong

Co-occurrence of Dominant Direct and Indirect Transitions in Low Temperature Sputtered Indium Tin Oxide Thin Films on Polymers

Indium tin oxide (ITO) layers are prepared on polymethylmethacrylate and polyethylene terephthalate by rf-magnetron sputtering at room temperature. Their 3D-AFM images and visible transmittance spectra are contrastively characterized and studied. An interesting morphological effect of the polymer substrates on their top ITO layers is observed. Dominant direct and indirect transition types deduced from optical spectra are surprisingly found in ITO films on different polymers. Furthermore, qualitative band structures are figured, and some theoretical discussions about the correlation of optical band structure, interface/surface morphology and carrier density are also presented.

Al/Cr 2 O 3 复合粉体的制备及红外反射特性研究

采用液相沉淀法, 制备了在片状铝粉表面包覆Cr 2 O 3 的复合粉体颜料, 利用XRD、SEM、UV/VIS/NIR分光光度计、FTIR红外光谱仪等方法对颜料相结构、形貌、光谱及红外反射特性等进行了测试表征。结果表明, Cr 2 O 3 包覆层对光谱反射特性的影响随波长变化而异, 波长越短, 包覆前后反射率的变化越大。当Cr 3+ :Al摩尔比为0.2:1.0时, Al/Cr 2 O 3 复合颜料在可见光波段的反射率下降接近50%, 颜色明度参数 L *降低15, 而8~14 μm波段红外反射率下降不到10%。分析表明, 包覆层对不同波长辐射的吸收系数以及表面粗糙度的差异导致了上述结果。该复合颜料对于低明度和光泽度的低红外发射率涂层设计有重要研究价值。采用液相沉淀法, 制备了在片状铝粉表面包覆Cr 2 O 3 的复合粉体颜料, 利用XRD、SEM、UV/VIS/NIR分光光度计、FTIR红外光谱仪等方法对颜料相结构、形貌、光谱及红外反射特性等进行了测试表征。结果表明, Cr 2 O 3 包覆层对光谱反射特性的影响随波长变化而异, 波长越短, 包覆前后反射率的变化越大。当Cr 3+ :Al摩尔比为0.2:1.0时, Al/Cr 2 O 3 复合颜料在可见光波段的反射率下降接近50%, 颜色明度参数 L *降低15, 而8~14 μm波段红外反射率下降不到10%。分析表明, 包覆层对不同波长辐射的吸收系数以及表面粗糙度的差异导致了上述结果。该复合颜料对于低明度和光泽度的低红外发射率涂层设计有重要研究价值。