低成本多晶硅片表面织构的研究

采用化学腐蚀液织构了经磷吸杂处理后的多晶硅片。利用SEM分析了化学腐蚀后多晶硅表面形态,并通过反射谱测试分析了多晶硅片表面的陷光效果。实验结果表明：经酸腐蚀后的样品表面分布着均一的“蚯蚓状”的腐蚀坑,且反射率较低。在400-1000nm波长范围内,反射率可达22．75％;生长了SiN,薄膜后,反射率减小至8．33％,比原始硅片的反射率低20．96％。     

Stretchable ITO-Free Organic Solar Cells with Intrinsic Anti-Reflection Substrate for High-Efficiency Outdoor and Indoor Energy Harvesting

Flexible photovoltaic devices are promising candidates for triggering the Internet of Things (IoT). However, the power conversion efficiencies (PCEs) of flexible organic photovoltaic (OPV) devices with high conductivity poly(3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) electrodes on plastic are lagging behind the rigid devices due to the low transmittance of polyethylene terephthalate (PET)/PEDOT:PSS. Moreover, the poor stretchability of the commonly used plastic substrates largely hinders the practical application of wearable devices. Herein, a novel stretchable indium tin oxide (ITO)-free OPV device with a surface-texturing polydimethylsiloxane (PDMS) substrate for outdoor strong- and indoor dim-light energy harvesting is reported. The high diffuse transmittance and haze effect of the substrate enable stretchable ITO-free devices, yielding a high PCE of 15.3% under 1 sun illumination. More excitingly, the stretchable device based on textured PDMS/PEDOT:PSS maintains a comparable PCE of 20.5% (20.8% for the rigid device) under indoor light illumination. Notably, the stretchable device is much more insensitive to the light direction, maintaining 38.5% of the initial PCE at an extremely small incident angle of 10° (16.3% for glass/ITO-based counterpart). The texturing stretchable substrate provides a new direction for achieving high performance and enhanced light utilization for the stretchable light-harvesting device, suitable for indoor and outdoor applications.     

Rigorous optical modeling and optimization of thin‐film photovoltaic cells with textured transparent conductive oxides

Typical thin‐film photovoltaic (PV) cells incorporate a textured transparent conductive oxide to enhance light trapping and efficiently harvest solar energy. Rigorous coherent optical simulations of these devices and a complete characterization of these textured films are a challenging problem because of the several orders of magnitude difference between the wavelengths of interest and the spatial dimension of the sample that needs to be evaluated. In this paper, a practical approach for rigorous and predictive modeling of optical properties of thin‐film PV cells incorporating a vast variety of light‐trapping structures including semi‐coherent textured films and patterned coherent structures is presented. In contrast to the existing semi‐empirical device models, it is demonstrated that the presented methodology can accurately predict the scattering properties of textured fluorine‐doped tin oxide and aluminum‐doped zinc oxide conductive transparent films. It is further shown that the optical response of single‐junction and tandem‐junction PV devices incorporating such films can also be predicted with good accuracy as compared with the measured results. Next, a methodology to identify the sufficient statistical fingerprints of semi‐coherent textured films that are needed to unambiguously predict the light propagation in thin‐film cells is presented. This comprehensive approach then lends itself to identifying the optimal surface morphology needed for strong light trapping. This rigorous approach automatically includes the effects of important loss mechanisms such as the surface plasmon‐enhanced absorption in textured metal surfaces that are otherwise very difficult to account for semi‐coherent approaches based on scalar scattering theory. Copyright © 2011 John Wiley & Sons, Ltd.     

光纤激光轧辊毛化工艺参数研究

针对CO₂激光器和YAG激光器的种种不足,采用光纤激光毛化柔性工作站,对轧辊表面进行了不同尺寸和分布的毛化点彤貌加工。分析了光纤激光功率、脉冲频率、脉冲宽度、扫描速度、离焦量等工艺参数对毛化点形貌的影响。结果表明:通过合理匹配毛化工艺参数,能够得到精确可控的轧辊毛化形貌和满足生产要求的粗糙度,也可以实现相对无序的毛化点排列。     

多晶Si太阳电池新型制绒工艺研究

提出一种采用二次酸腐蚀的多晶Si制绒新方法,首先在HF/HNO3的富HNO3体系中对Si片进行一次腐蚀,之后在富HF体系中进行二次腐蚀,以优化表面织构,减少光在Si表面的反射损失。制绒后,用扫描电子显微镜(SEM)对Si片进行了表面形貌分析,用Carry 5000紫外-可见-近红外分光光度计测量反射谱线,得到未镀减反射膜(ARC)的二次腐蚀制绒的最低反射率为20.34%,比一次腐蚀制绒(22.70%)低2.36%。将二次腐蚀新工艺应用于太阳电池工业制备中,对电池输出参量进行检测分析。结果表明,经过二次腐蚀工艺处理的太阳电池开路电压(VOC)、短路电流(JSC)和效率η均比采用一次腐蚀工艺的太阳电池有不同程度的提高,制成的太阳电池最高效率为14.93%。     

Surface texturing of GaAs using a nanosphere lithography technique for solar cell applications

In this study, we present novel methods to texture the surface of GaAs substrates using the nanosphere lithography (NSL) technique that is based on arrays of SiO₂ nanospheres. Closed-packed arrays of SiO₂ nanospheres were formed on a benzocyclobutene (BCB) layer, followed by embedding SiO₂ nanospheres into the BCB layer. To texture the GaAs surface, three patterns were fabricated by nanosphere lithography. First, a convex pattern from the shape of the nanospheres was produced on the surface of GaAs. Second, a concave shape was produced on the surface of GaAs by additional wet etching to remove SiO₂ nanospheres. These two methods were found to be effective in reducing the reflectance to a range of 400-800 nm. Finally, the arrays of SiO₂ nanospheres were transferred onto the GaAs by dry-etching using a mixture of Cl₂ and BCl₃ gases, resulting in arrays of GaAs nanorods. The dry-etched surface structure showed the lowest reflectance.     

涤纶DTY退绕性能试验方法

通过模仿涤纶DTY在织布工厂的使用过程,制作简单试验装置,制定试验规程,对涤纶DTY进行退绕性能试验,验证原料、工艺、设备等加工条件变化时产品的退绕性能是否有影响,及时发现和解决问题,从而提高产品质量。     

Friction and wear performances of Si3N4 ceramic matrix composites: A review from the perspectives of doped phase,layered structure design,and laser surface texturing

Si₃N₄ ceramic matrix composites (SN-CMCs) have been designed and widely used in many engineering fields under externally loading conditions. It is well known that the wear of materials is closely related to components’ mechanical reliability and service life. Understanding of the friction and wear performances is very important to provide insights into how to improve the wear resistance of materials. Coefficient of friction and wear rate, in general, are the most critical parameters of tribological behavior of materials. In this paper, friction and wear performances of SN-CMCs are reviewed from the perspectives of doped phase, layered structure design, and laser surface texturing. The article describes the change of friction and wear performances of SN-CMCs sintered with different additive phases. Tribological behavior of SN-CMCs with engineering designed layered structure is also analyzed from the aspects of surface coating and gradient structure. In addition, friction and wear performances of SN-CMCs under different lubrication conditions are also discussed. As an ideal processing method for hard and brittle ceramic materials, laser surface texturing has been proved to be an effective way to improve the wear resistance of SN-CMCs. Researches have shown that the better wear resistance can be obtained by combining laser surface texture with layered structure. At the end of paper, studies on friction and wear performances of SN-CMCs are summarized and prospected.     

防紫外线细旦丙纶DTY生产工艺

研究了防紫外线细旦丙纶DTY生产工艺及其对纤维性能的影响。选择变形速度 40 0～5 0 0m/min ,拉伸倍数 1.4～ 1.6,D/Y比 1.60 ,第一热箱温度 ( 15 0± 5 )℃ ,第二热箱温度 12 0～ 13 0℃ ,纤维品质优良 ,一等品率达 95 % ,紫外线遮挡率大于 99%。     

涤纶加弹机假捻皮圈的合理使用

对涤纶加弹机假捻皮圈假捻工艺参数的设定进行了探讨,研究了皮圈状况对DTY的物理指标、染 色状况和解捻张力的影响,提出通过调整皮圈表面线速度与丝条速度之比值,可弥补由于皮圈磨损对丝条染 色性能造成的不良影响。