八异戊氧基-2,3-萘酞菁镍旋涂膜对NO2的气敏特性

为了设计对NO2气体具有高灵敏度、可逆性和专一选择性的敏感材料和克服敏感膜制作工艺复杂的缺点,利用旋涂技术制备了八异戊氧基-2,3-萘酞菁镍(N iNc(iso-PeO)8)气敏薄膜,采用AFM观察其表面形貌,研究了N iNc(iso-PeO)8旋涂膜对NO2的气敏性,分析了薄膜形貌和测试温度等因素对薄膜气敏性的影响.结果表明,旋涂溶液浓度较低时制备的薄膜表面均匀,平整度较好,萘酞菁分子以无序聚集形式排列在基片上.工作温度升高,薄膜对NO2的响应恢复能力增强;不同温度下N iNc(iso-PeO)8旋涂膜对NO2灵敏度的顺序为:20℃<50℃<75℃<100℃>130℃.     

旋涂法制备碳纳米管阴极及其场发射性能的测试

采用Y2O3和Ni 作催化剂,在H2和He混合气体气氛下通过弧光放电法得到高纯度的单壁碳纳米管.在用热氧化提纯法对高纯度碳纳米管产物进行进一步提纯后,用这种碳纳米管粉末与酒精配制成悬浮液,通过旋涂、干燥、退火等工艺得到碳纳米管阴极薄膜.I-V测试表明用该法得到的碳纳米管薄膜具有良好的电子场致发射性能.     

旋涂法制备PVDF/PTFE复合膜及其性能研究

旋涂技术具备薄膜厚度精确可控、高性价比、节能、低污染等优点,在薄膜制备方法中脱颖而出。本文使用旋涂法制备了聚偏氟乙烯(PVDF)/聚四氟乙烯(PTFE)复合膜,并对其制备工艺进行了优化,同时对旋涂成膜机理进行了研究。通过单因素试验,分析了PVDF溶液浓度、旋涂仪的旋转速度和成膜温度对复合膜的拉伸强度和水通量的影响,利用电子扫描显微镜(SEM)对复合膜胶粘层的微孔孔径变化进行了分析,结果表明,PVDF/PTFE复合膜制备的最佳工艺:PVDF溶液浓度为6 g/L,旋涂仪的旋转速度为2500 r/min以及成膜温度为90℃。该条件下制备的复合膜的膜厚度为200μm,平均孔径为20μm,拉伸强度可达到26.34MPa,水通量可达到605.2 L/(m2·h)。此外,分析旋涂PVDF/PTFE复合膜成型的机理,其原因是由于PVDF溶胶分子与PTFE基膜之间存在范德华力等分子间力以及溶胶分子渗透到基膜微孔之间所形成的钩钉键等粘合作用。     

八异戊氧基金属萘酞菁配合物旋涂膜的气敏性研究

用旋涂技术成功制备了一类新型萘酞菁配合物（八异戊氧基-2，3-金属萘酞菁）气敏薄膜．对薄膜进行了AFM分析，结果表明，薄膜表面均匀、平整。首次系统研究了萘酞菁配合物旋涂膜对NO2的气敏性，100℃时薄膜对NO2具有较好的响应、可逆性以及较快的响应和恢复时间。分析了配合物的中心金属对气敏性能的影响。     

CoFe_2O_4薄膜厚度对其微结构和磁性能的影响

以铁和钴的硝酸盐为主要原料,采用sol-gel旋涂法在Si(001)基片上制备了不同厚度的CoFe2O4(CFO)薄膜。研究了薄膜厚度对其结构、形貌及磁性能的影响。结果表明:随着其厚度的增大,薄膜的结晶度变好,薄膜晶粒度逐渐增大到70nm。Ms随着薄膜厚度的增大先增大后减小;Hc的变化规律和Ms相反。当薄膜厚度为800nm时,Ms达到最大值59.2A·m2/kg,此时Hc最小为106.7kA/m。该薄膜具有高度的平行各向异性。     

聚合物发光器件的旋涂膜厚模型研究

聚合物膜厚的控制对于优化聚合物发光器件的光电性能是至关重要的.应用最小二乘法,通过对中心复合设计实验数据的拟合,建立了旋涂法制备聚合物薄膜的膜厚回归模型.测试结果表明:利用该模型所得到的预测膜厚与旋涂的实测膜厚基本相符.膜厚模型的建立,对于旋涂工艺中旋涂条件的选择、薄膜厚度的控制以及器件性能的优化具有一定的实用价值.     

Excellent Intrinsic Long-Term Thermal Stability of Co-Evaporated MAPbI3 Solar Cells at 85 °C

Thermal stability is a critical criterion for assessing the long-term stability of perovskite solar cells (PSCs). Here, it is shown that un-encapsulated co-evaporated MAPbI₃ (TE_MAPbI₃) PSCs demonstrate remarkable thermal stability even in an n-i-p structure that employs Spiro-OMeTAD as hole transport material (HTM). TE_MAPbI₃ PSCs maintain over ≈95% and ≈80% of their initial power conversion efficiency (PCE) after 1000 and 3600 h respectively under continuous thermal aging at 85 °C. TE_MAPbI₃ PSCs demonstrate remarkable structural robustness, absence of pinholes, or significant variation in grain sizes, and intact interfaces with the HTM, upon prolonged thermal aging. Here, the main factors driving TE_MAPbI₃ stability are assessed. It is demonstrated that the excellent TE_MAPbI₃ thermal stability is related to the perovskite growth process leading to a compact and almost strain-stress-free film. On the other hand, un-encapsulated PSCs with the same architecture, but incorporating solution-processed MAPbI₃ or Cs_0.05(MA_0.17FA_0.83)_0.95Pb(I_0.83Br_0.17)₃ as active layers, show a complete PCE degradation after 500 h under the same thermal aging condition. These results highlight that the control of the perovskite growth process can substantially enhance the PSCs thermal stability, besides the chemical composition. The TE_MAPbI₃ impressive long-term thermal stability features the potential for field-operating conditions.     

Characterization of the phases and morphology in synthesizing Cu2-xSe and CuSe films

ABSTRACT

Copper Selenides are important semiconductor materials with excellent performance. Cu_2-xSe and CuSe films were synthesized by spin-coating and chemical co-reduction method. The phases of product films were analyzed by X-ray diffraction (XRD) and the morphology was characterized by scanning electron microscopy (SEM), and the compositions of products were analyzed by energy dispersive spectroscopy (EDS). The surface resistance of the product film was measured using a four-probe resistance instrument. When Copper chloride was chosen as copper source, the products contain Cu_2-xSe, CuSe and a small amount of NaCl. When the reacting temperature is below 180 °C, the XRD intensity of impurity phase NaCl is obviously increased, while it is easier to produce Cu₂Se film at 200 or 220 °C. The sample obtained at 160 °C for 20 h consists of about 0.3 ～ 0.5 µm particles, while the sample obtained at 220 °C shows about 2 ～ 4 µm flake crystals; When the copper nitrate is used as a raw material, the XRD peaks of the product obtained at 200 °C for 20 h are much high and sharp, the phases obtained are mainly CuSe. The sample obtained at 200 °C consists of hexagonal flaky crystals with about 2 ～ 3 µm diameters, while it consists of particles with about 0.3 ～ 0.5 µm diameters for the sample obtained at 220 °C. In addition, the longer reaction time is conducive to the copper selenide formation, for example the single phase CuSe film can be obtained at 220 °C. The average resistivity of Cu-Se films synthesized at 200 °C for 20 h is 2.12E-3 Ω·cm.     

Efficient lead acetate sourced planar heterojunction perovskite solar cells with enhanced substrate coverage via one-step spin-coating

In planar heterojunction (PHJ) perovskite solar cells (PerSCs) without mesoporous metal oxide skeleton, there is challenge of formation perovskite film with full coverage to the conductive substrate through solution-process the lead halide precursors. Selecting a lead source with more volatile byproducts is an effective approach to obtain much smoother films with smaller and fewer pinholes. Herein, we demonstrate efficient CH₃NH₃PbI₃/PCBM PHJ PerSCs by using lead acetate (Pb(Ac)₂) as lead precursor. The morphology of the perovskite thin films were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively, and the crystalline quality of the perovskite films were investigated by X-ray diffraction (XRD) spectroscopy. Time-resolved photoluminescence (TRPL) was used to investigate the PL lifetime of the perovskite film. The perovskite film derived from Pb(Ac)₂ shows enhanced surface coverage and improved photoluminescence lifetime in comparison with PbI₂ sourced perovskite film. Averaged over 20 individual devices, the power conversion efficiency (PCE) of devices derived from Pb(Ac)₂ reaches 14.81%, much higher than PbI₂ sourced devices by one-step (8.23%) or two-step (10.58%) spin-coating.     

离心法曲面涂胶的胶层厚度研究

曝光工艺中经离心涂敷后抗蚀剂胶层的均匀性对曝光线宽有很大的影响.为了得到高速旋转下抗蚀剂胶体在凹面衬底上所形成膜层厚度的均匀性,在凹面衬底上建立了非牛顿流体微元经离心旋转的流体动力学模型.根据对应的边界条件、非牛顿流体的本构方程和连续性方程,推导并得到了流体性质、曲面面形、旋转速度和时间等因素与最终厚度的关系式.使用流...