InAs0.96Sb0.04红外薄膜的光学性质研究

采用水平滑移石墨舟液相外延生长技术在n型(100)InAs衬底上生长了InAs0.96Sb0.04薄膜.在1.5~5.5 eV光子能量范围采用紫外—可见光椭圆偏振光谱仪于室温下测试了其介电函数谱ε(E).基于电子带间跃迁和联合态密度理论,采用S.Adachi的MDF模型对ε(E)进行了拟合,并计算了各种临界点电子跃迁对ε(E)的贡献.结果表明:实验数据与模型吻合得非常好,E1和E1 Δ1跃迁发生在布里渊区(BZ)的Λ轴或L点,分别对应于M1型临界点Λ5v→Λ6c(或L4v.5→L6c)和Λ6v→Λc6(或L6v→L6c)跃迁;E2跃迁是由于M1型和M2型鞍点能量简并引起的,沿着BZ的Σ和Δ轴方向.     

Microstructures and optical properties of solgel derived Ba0.9Sr0.1TiO3 thin films formed by different annealing process

We investigated the effect of annealing process on microstructures and optical properties of the sol-gel derived Ba_0.9Sr_0.1TiO₃ (BST) films. The BST films, fabricated by layer-by-layer high-temperature (? 650 °C) annealing process, had laminated structures consisting of alternating dense and porous BST layers, and exhibited excellent optical performance as Bragg reflectors. The Bragg reflection characteristic can be enhanced with increasing annealing temperature. Those BST films fabricated at temperatures lower than 650°C displayed uniform cross-sectional morphologies even treated at a higher temperature. The difference in the microstructures of the BST thin films was also discussed.     

Ar+刻蚀对InGaAs,n-InP和p-InP表面损伤及消除

研究了Ar+刻蚀对InGaAs,n-InP和p-InP表面的损伤,并用湿法腐蚀后处理消除损伤.Ar +刻蚀后InGaAs表面均方根粗糙度较小,而n-InP和p-InP表面明显变粗糙.刻蚀后InGaAs PL强度增加,而n-InP和p-InP PL强度都减小.用XPS分析了未刻蚀、Ar+刻蚀和湿法腐蚀后处理三种情况下样品表面原子含量.刻蚀后InGaAs表面In和Ga含量明显增加,n-InP和p-InP表面有严重P缺失.湿法腐蚀后,样品表面原子含量和未刻蚀前基本一致.     

退火工艺对钛酸锶钡铁电多层膜结构与物性的影响

立足于无铅型钛酸锶钡(BST)铁电多层膜的制备及物性研究.采用溶胶-凝胶方法制备了Ba0.9Sr0.1TiO3铁电多层膜,并利用快速退火炉对多层膜进行热处理.重点分析两种不同热处理工艺对钛酸锶钡多层膜微观结构及相关物理性能的影响.通过X射线衍射(XRD),扫描隧道显微镜(SEM)及可见光范围反射谱测量等的表征方法,研究钛酸锶钡铁电多层膜微观结构的演化和形成机理,为制备性能优良的钛酸锶钡铁电多层膜提供基础数据.     

高反射率周期性铁电多层膜形成机理研究

利用含聚合物添加剂的前驱体溶液,通过重复甩胶镀膜—热处理工艺制备了PbZrB0.4BTiB0.6B0.6OB3(PZT)和BaTi0.9Sr0.1BO3(BST)铁电多层膜.在特定的波长范围,每个多层膜具有高达90%的光学反射率,且峰值反射率随生长次数的增加而增大.显微技术分析表明每个多层膜是由一系列厚度几乎相等的致密层和厚度也近乎相同的多孔层交替排列形成的一维周期性结构.重点分析了这种周期性结构的可能形成机理,它涉及相分离和高分子聚合物热解两个过程.     

Ar+刻蚀对InGaAs, n-InP和p-InP表面损伤及消除

研究了Ar+刻蚀对InGaAs, n-InP和p-InP表面的损伤，并用湿法腐蚀后处理消除损伤. Ar+刻蚀后InGaAs表面均方根粗糙度较小，而n-InP和p-InP表面明显变粗糙. 刻蚀后InGaAs PL强度增加，而n-InP和p-InP PL强度都减小. 用XPS分析了未刻蚀、Ar+刻蚀和湿法腐蚀后处理三种情况下样品表面原子含量.刻蚀后InGaAs表面In和Ga含量明显增加，n-InP和p-InP表面有严重P缺失. 湿法腐蚀后，样品表面原子含量和未刻蚀前基本一致.     

Effects of LaNiO<Subscript>3</Subscript> interlayer on the microstructures and electrical properties of Ba<Subscript>0.9</Subscript>Sr<Subscript>0.1</Subscript>Ti<Subscript>0.99</Subscript>Mn<Subscript>0.01</Subscript>O<Subscript>3</Subscript> multilayer

The aim of this work was to investigate the effects of low-resistivity interlayer on the physical properties of periodic Ba_0.9Sr_0.1Ti_0.99Mn_0.01O₃ (BSTM) multilayers prepared by a chemical solution deposition method. A LaNiO₃ (LNO) layer was inserted into the periodic BSTM multilayer artificially to form a sandwiched configuration of BSTM/LNO/BSTM. The capacitances at low frequencies (<100 kHz) of the sandwiched multilayer are significantly enhanced compared to that of the pure BSTM multilayer. The space charge accumulated at the LNO layer was proposed to explain the enhancement based on Maxwell-Wagner (M-W) model. However, LNO interlayer leads to an increase in the leakage current. A non-Ohmic conduction region is observed for BSTM/LNO/BSTM multilayer when the electric field exceeds 100 kV/cm. The results offer a new approach to achieve dielectric films with high dielectric constant.     

Ar+刻蚀对InGaAs,n-InP和p-InP表面损伤及消除

研究了Ar 刻蚀对InGaAs,n-InP和p-InP表面的损伤,并用湿法腐蚀后处理消除损伤.Ar 刻蚀后InGaAs表面均方根粗糙度较小,而n-InP和p-InP表面明显变粗糙.刻蚀后InGaAs PL强度增加,而n-InP和p-InP PL强度都减小.用XPS分析了未刻蚀、Ar 刻蚀和湿法腐蚀后处理三种情况下样品表面原子含量.刻蚀后InGaAs表面In和Ga含量明显增加,n-InP和p-InP表面有严重P缺失.湿法腐蚀后,样品表面原子含量和未刻蚀前基本一致.