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21.
Control of blend morphology at multi-scale is critical for optimizing the power conversion efficiency (PCE) of plastic solar cells. To better understand the physics of photoactive layer in the organic photovoltaic devices, it is necessary to gain understanding of morphol- ogy and the corresponding electronic property. Herein we report the correlation between nanoscale structural, electric properties of bulk heterojunction (BHJ) solar cells and the annealing-induced PCE change. We demonstrate that the PCE of BHJ solar cells are dramatically improved (from 1.3 % to 4.6 %) by thermal annealing, which results from P3HT crystalline stacking and the PCBM aggregation for interpenetrated network. The similar trend for annealing- induced photovoltage and PCE evolution present as an initial increase followed by a decrease with the annealing time and temperature. The surface roughness increase slowly and then abruptly after the same inflection points observed for photovoltage and PCE. The phase images in electric force microscopy indicate the optimized P3HT and PCBM crystallization for interpenetrating network formation considering the spectroscopic results as well. From the correlation between surface photovoltage, blend morphology, and PCE, we propose a model to illustrate the film structure and its evolution under different annealing conditions. This work would benefit the better design and optimization of the morphology and local electric proper- ties of solar cell active layers for improved PCE. 相似文献
22.
采用阻燃芳纶/粘胶混纺纱作为表经表纬,普通纯棉纱线作为里经里纬,设计并成功织造了五种表层阻燃、里层舒适的阻燃双层机织物试样.通过对试样进行阻燃性能测试,结果表明,五种试样的阻燃性能均达到GB 8965《阻燃防护服》的要求.对试样进行导水性、透湿性和透气性能测试,结果表明,五种试样的舒适性能都符合服用面料的要求.在今后的研究中,适当减小织物的克重、提高织物的经密,将能研制出更适合防护服要求的面料. 相似文献
23.
Thermal–physical property is one of the most important properties of materials. The conventional frequency-domain photoacoustic piezoelectric(PAPE) technique has been developed as an important method for thermal diffusivity determination. In this paper, the PAPE technique is extended to time domain(TD). First, based on a simplified thermoelastic model, the TD PAPE theory under square-wave-modulated excitation was developed,the dependence of the TD PAPE signal on modulation frequency as well as material parameters was obtained, and the determination of thermal diffusivity was simulated and theoretically analyzed. Second, the experimental system and the corresponding measurement method were established. Third, thermal diffusivities of various standard samples, such as copper, aluminum, and nickel, were measured, and the effectiveness of the technique was verified. The results show that the TD PAPE technique can provide a simple, fast and effective way for thermal diffusion study. 相似文献
24.
Fe62Co8 xMxZr6Nb4Ge1B19(M=Mo, Cr) bulk metallic glasses were synthesized in the diameter range up to 2 mm by copper mold casting,which exhibit high thermal stability and large glass-forming ability. The super-cooled liquid region diminishes by the dissolution of Mo. The addition of 2 at% Cr leads to the broading of the liquid region remarkably, resulting in the improvement of thermal stability. The crystallization takes place through a single exothermic reaction, accompanying the precipitation of more than three kinds of crystallized phases such as α-Fe,Fe2Zr and ZrB2. The Fe-based alloys show soft ferromagnetic properties. The saturation magnetization(ss) decreases with increasing Mo or Cr content while the saturated magnetostriction increases with raising Mo or Cr content. There is no evident change in the ssand coercive force(Hc)with annealing temperature below the crystallization temperature, which suggests a more relaxed atomic configuration the glasses have. The crystallization causes a substantial enhancement in both ssand Hc. Each soft magnetic property of the glasses containing Cr with higher thermal stability is superior to that of the alloys containing Mo. 相似文献
25.
In order to improve the anti-oxidation of C/C composites, a SiC–MoSi2multi-phase coating for SiC coated carbon/carbon composites(C/C)was prepared by low pressure chemical vapor deposition(LPCVD) using methyltrichlorosilane(MTS) as precursor, combined with slurry painting from MoSi2 powder. The phase composition and morphology were analyzed by scanning electron microscope(SEM) and X-ray diffraction(XRD) methods, and the deposition mechanism was discussed. The isothermal oxidation and thermal shock resistance were investigated in a furnace containing air environment at 1500 1C. The results show that the as-prepared SiC–MoSi2coating consists of MoSi2 particles as a dispersing phase and CVD–SiC as a continuous phase. The weight loss of the coated samples is 1.51% after oxidation at 1500 1C for 90 h, and 4.79% after 30 thermal cycles between 1500 1C and room temperature. The penetrable cracks and cavities in the coating served as the diffusion channel of oxygen, resulted in the oxidation of C/C composites, and led to the weight loss in oxidation. 相似文献
26.
应用分子动力学模拟方法研究了2,4,6-三硝基甲苯(TNT)在纯高温下的分解机理,研究结果表明TNT初始分解机理主要为C-NO2键的断裂和NO2-ONO重新排列导致O-N键发生断裂,然后发生H原子转移反应形成H2O,HONO和HO分子;通过对TNT热分解反应物和生成物的研究结果表明N2和H2O分子是TNT分解过程中最稳定的生成物,NO2,NO和HONO分子为TNT热分解过程中的中间产物;在高温4500K,CO,H2,CO2和OH分子出现的频率逐渐提高,表明这几种分子在高温下更容易形成. 相似文献
27.
为提高避险人员的生存舒适品质,建立基于密闭小空间的载人试验,对人体热舒适的温湿度耦合影响进行了定量分析和研究,验证了避难硐室配置制冷除湿装置的必要性,并对硐室内温湿度的主要扰动源进行分析和计算.采用CFD技术,构建了氧气瓶供氧时的避难硐室三维模型.模拟结果表明:无空调时避难硐室温湿度在9h内能达到33℃,90%,即人体闷热的环境条件;通过制冷除湿装置能有效地将其控制在30℃,83%以下.通过现场载人试验,验证了数值模拟的可靠性,并得硐室内温度达到28℃时,相对湿度应控制在80%以下.为避险设施设计提供指导性依据. 相似文献
28.
文章用水热法合成了含氯方钠石粉末,并讨论了 NaCI的掺杂浓度、晶化时间和晶化温度对方钠石结构的影响。通过X射线衍射(XRD),扫描电镜(SEM)和热重分析(TG -DTA -DSC)对合成方钠石结构、形貌和热稳定性进行分析。结果表明,NaCI的掺杂量在2%~10%内合成样品产物为单一方钠石结构,当掺杂量达到20%时,合成产物结构发生变化,最佳晶化温度为80℃,晶化时间为6h。扫描电镜图片显示样品颗粒均匀,粒径为01.~02.μm。热重分析表明样品在230℃附近有吸热反应。 相似文献
29.
由"热致失效"介绍电子设备散热的重要性及方式,通过将模型简化及热管位置的方案规划,经CFD仿真软件对各方案进行分析并对比结果,以此得出适合的最优化设计。 相似文献
30.