硅薄膜矩形空芯波导太阳能电池光捕获性能的研究

为提高薄膜电池对光的捕获能力, 将平面硅薄膜电池制 作成矩形空芯波导结构,对其太阳光注入方式、光捕获能力和光-电转换效能进行了理论和 实验探讨。基于 多层膜反射理论和波导反射模型对波导电池光捕获效果的预测表明,波导电池能够将入射光 限制在空芯结 构内多次反射和吸收,具有较平面电池更高的光捕获能力。测定了不同平行光束在不同入射角度 下平面和波导 电池的光捕获功率和光-电转换效能的结果表明,波导电池对入射光功率近似全部捕获,其 光-电功率转换效能 较对应的平面电池有3～5倍的提升。对不同截面尺寸和长度的单结空芯波导电池光捕获率 进行了计算,提 出从电池膜层结构和空芯几何尺寸参数优化硅薄膜矩形空芯波导电池的思路,通过优化有 望实现用小于多结平面电池外形尺寸的单结空芯波导电池达到更好的光捕获效果。     

ZnO薄膜材料的发光特性

回顾了最近几年对 Zn O薄膜材料发光特性的研究进展 ,介绍了用不同方法制备 Zn O薄膜的自发辐射和受激辐射发光特性。     

Metal-Organic Framework Thin Films Grown on Functionalized Graphene as Solid-State Ion-Gated FETs

The unique properties of 2D-materials like graphene are exploited in various electronic devices. In sensor applications, graphene shows a very high sensitivity, but only a low specificity. This shortcoming can be mastered by using heterostructures, where graphene is combined with materials exhibiting high analyte selectivities. Herein, this study demonstrates the precise deposition of nanoporous metal-organic frameworks (MOFs) on graphene, yielding bilayers with excellent specificity while the sensitivity remains large. The key for the successful layer-by-layer deposition of the MOF films (SURMOFs) is the use of planar polyaromatic anchors. Then, the MOF pores are loaded with ionic liquid (IL). For functioning sensor devices, the IL@MOF films are grown on graphene field-effect transistors (GFETs). Adding a top-gate electrode yields an ion-gated GFET. Analysis of the transistor characteristics reveals a clear Dirac point at low gate voltages, good on-off ratios, and decent charge mobilities and densities in the graphene channel. The GFET-sensor reveals a strong and selective response. Compared to other ion-gated-FET devices, the IL@MOF material is relatively hard, allowing the manufacturing of ultrathin devices. The new MOF-anchoring strategy offers a novel approach generally applicable for the functionalization of 2D-materials, where MOF/2D-material hetero-bilayers carry a huge potential for a wide variety of applications.     

Growth-temperature-dependent optical and acetone detection properties of ZnO thin films

Zinc oxide (ZnO) thin films were prepared onto glass substrates at moderately low growth temperature by two-stage spray pyrolysis technique. The effects of growth temperature on structural, optical and acetone detection properties were investigated with X-ray diffractometry, a UV-visible spectrophotometer, photoluminescence (PL) spectroscopy and a homemade gas sensor testing unit, respectively. All the films are polycrystalline with a hexagonal wurtzite phase and exhibit a preferential orientation along [002] direction. The film crystallinity is gradually enhanced with an increase in growth temperature. The optical measurements show that all the films are physically highly transparent with a transmittance greater than 82% in the visible range. The band gap of the film is observed to exhibit a slight red shift with an increasing growth temperature. The PL studies on the films show UV/violet PL band at ～ 395 nm. Among all the films investigated, the film deposited at 250 ℃ demonstrates a maximum sensitivity of 13% towards 20 ppm of acetone vapors at 300 ℃ operating temperature.     

一种新型BST薄膜移相器的电路设计

采用铁电材料钛酸锶钡(BST)的薄膜移相器以其成本低廉、响应速度快、频带宽、体积小、重量轻、控制简单等诸多优点而引起关注.本文对BST薄膜移相器的设计模型进行研究分析,提出了一种新型的电路结构,在BST材料移相器的大移相量和尽可能低的损耗一对矛盾中找到一个平衡点.并通过ADS仿真验证了这一新型电路.     

含氢非晶碳膜(a-C:H)红外光学特性的研究

采用端部霍尔离子源在硅基底上制备了含氢非晶碳膜（a-C:H）,并测量了4 000~1 500 cm-1的红外透射光谱。基于单层薄膜的透射关系,获得了仅有六个拟合参数的光学常数计算模型。利用该模型,可以同时获得薄膜在宽波段范围内的光学常数和厚度:折射率的最大值为1.94,消光系数的最大值为0.014 9,拟合薄膜厚度为617 nm 。     

用于SAW器件的C轴择优取向LiNbO3薄膜的制备及结构研究

采用射频（RF）磁控溅射法在金刚石（111）衬底上沉积LiNbO3（LN）薄膜,借助X射线衍射技术（XRD）,研究了外加偏压（0～80V）和衬底温度（200～500℃）等工艺参数对LiNbO3薄膜结构和取向性的影响。实验结果表明,在衬底温度为200℃、外加偏压为～80V的T艺条件下,LiNbO3的（006）衍射峰强度超过LN的（012）衍射峰强度,在金刚石（111）衬底上获得较高c轴取向的LN薄膜。并且对C轴择优取向LN薄膜的形成机理进行了探讨。     

表面加工多晶硅薄膜热扩散系数的在线提取

提出了一种在线提取多晶硅薄膜热扩散系数的简单测量方法,测试结构可随表面器件工艺加工制作,无需附加工艺。通过分析两个长度相同、宽度与厚度相同梁的瞬态冷却特性,获得其冷却时的温度衰减时间常数,便可以提取出表面加工多晶硅薄膜的热扩散系数。给出了瞬态冷却热电分析模型,综合考虑了梁冷却过程中各种散热因素即对流、辐射以及向衬底传热的影响。实验测得的该表面加工多晶硅薄膜热扩散系数是0.165 cm2-s 1(方块电阻是116.25Ω/sq)。该方法能够实现多晶硅薄膜热扩散系数的在线测试。     

光催化活性TiO2薄膜的研究进展

讨论了影响TiO2薄膜光催化性能的主要因素,如TiO2薄膜的晶体结构、晶粒尺度以及薄膜表面积和厚度等。介绍了提高TiO2薄膜光催化活性的三种主要途径,包括表面预处理、复合半导体以及金属沉积。对TiO2薄膜几种重要的制备方法和应用事例进行了叙述,并展望了此功能薄膜的应用前景。     

Ultra-Stable and Sensitive Ultraviolet Photodetectors Based on Monocrystalline Perovskite Thin Films

The detection of ultraviolet (UV) radiation with effective performance and robust stability is essential to practical applications. Metal halide single-crystal perovskites (ABX₃) are promising next-generation materials for UV detection. The device performance of all-inorganic CsPbCl₃ photodetectors (PDs) is still limited by inner imperfection of crystals grown in solution. Here wafer-scale single-crystal CsPbCl₃ thin films are successfully grown by vapor-phase epitaxy method, and the as-constructed PDs under UV light illumination exhibit an ultralow dark current of 7.18 pA, ultrahigh ON/OFF ratio of ≈5.22 × 10⁵, competitive responsivity of 32.8 A W⁻¹, external quantum efficiency of 10867% and specific detectivity of 4.22 × 10¹² Jones. More importantly, they feature superb long-term stability toward moisture and oxygen within twenty-one months, good temperature tolerances at low and high temperatures. The ability of the photodetector arrays for excellent UV light imaging is further demonstrated.