Ca^2＋对KDP晶体的光损伤阈值的影响

Ca2 是KDP原料中一种常见的杂质离子,这种杂质不仅会影响晶体的生长过程,而且会加重晶体的光散射.通过传统降温法和点籽晶快速生长法生长不同Ca2 掺杂浓度的KDP晶体样品,对样品进行激光损伤实验,结果表明,Ca2 的存在降低了KDP晶体的光损伤阈值,其原因主要在于Ca2 掺杂导致晶体内部缺陷增多,内应力增加以及晶体中的散射颗粒密度增大使晶体光吸收加重.     

多晶Cu(In,Ga)Se2薄膜太阳电池光强特性的研究

本文系统研究了Cu(In,Ga)Se2(CIGS)薄膜太阳电池在入射光强为10～100 mW/cm2范围内的性能参数.结果表明,随光强的减弱,CIGS电池的转换效率、填充因子、短路电流密度和开路电压等性能参数逐步衰减;电池参数与光强的依赖关系可明显划分为两个阶段:光强高于75 mW/cm2时,电池性能变化不大;当光强低于70 mW/cm2时,电池性能衰减明显.这是由于随着光强的降低,RS(串联电阻)值和RSH(并联电阻)值都在升高.其中,RSH值的增大使得CIGS电池的弱光特性变好,但较小的RSH值并不能弥补RS所导致电池性能的衰退.最后,发现高Ga含量的CIGS薄膜电池(8.7;)比低Ga含量(6.9;)的电池弱光特性好.     

CdS薄膜中"白斑"的研究

本论文对CdS薄膜中的"白斑"进行了研究.化学水浴沉积法(CBD)制备CdS薄膜所需要的化学反应物包括硫脲、氨水、镉盐和铵盐等.文中采用两种镉盐和铵盐来沉积CdS薄膜:氯化镉和氯化铵,乙酸镉和乙酸铵.所沉积的CdS薄膜的表观形貌由SEM表征,成分由EDX表征.当镉盐和铵盐分别采用氯化镉和氯化铵时,生成的薄膜中存在大量的"白斑".这些"白斑"的成分不是CdS,而是(CdCl)2S.增加氨水的浓度可以大大减少这些"白斑",但是不能彻底消除这些"白斑".当镉盐和铵盐分别采用乙酸镉和乙酸铵时,生成的薄膜均匀、平整,薄膜中根本就不存在所谓的"白斑".因此,沉积CdS薄膜时,镉盐和铵盐不宜采用氯化镉和氯化铵,应该采用乙酸镉和乙酸铵.     

衬底对Cu(In,Ga)Se2薄膜织构的影响

分别在苏打石灰玻璃、Mo箔、无择优取向的Mo薄膜以及(110)择优取向的Mo薄膜四种不同衬底上，采用共蒸发工艺沉积约2 μm厚的Cu(In,Ga)Se₂薄膜，用X射线衍射仪测量薄膜的织构，研究衬底对Cu(In,Ga)Se₂薄膜织构的影响.在以上四种衬底上沉积的Cu(In,Ga)Se₂薄膜的(112)衍射峰强度依次逐渐减弱，(220/204)衍射峰从无到有且强度逐渐增强.在苏打石灰玻璃和Mo箔衬底上的Cu(In,Ga)Se_{2关键词： 择优取向 Cu(In 2}薄膜')" href="#">Ga)Se₂薄膜 太阳电池     

稀土改质催化剂对废食用油制备燃料油的影响

利用浸渍法制备稀土改质催化剂,用于废食用油脂催化裂解的裂解气催化改质。考察了催化剂活性组分含量、硅铝比、焙烧温度、改质反应温度对产物组成、烯烃含量及收率的影响。得最佳条件:ZSM-5作为催化剂载体,催化剂活性组分镧稀土含量为6%,催化剂焙烧温度为550℃,改质反应温度为360℃。在最佳条件下催化改质,燃料油烯烃含量降低了34.3%,汽油含量提高了14.36%,轻柴油含量提高了1.67%,重柴油含量下降了6.72%,重油含量下降了2.2%,燃料油总收率提高了7.12%,油品质显著提高。     

氦原子高激发态的塞曼效应

利用塞曼哈密顿的球张量形式以及塞曼哈密顿在耦合表象中的矩阵元公式,在考虑磁场二次项作用的基础上,研究了氦原子n3P(n=4,5)高激发态的塞曼效应,给出解析解,并绘出了塞曼能级分裂图.     

基于物理中面FGM板屈曲的有限元分析

基于物理中面的概念,根据最小势能原理推导了功能梯度材料FGM薄板屈曲的有限元控制方程,求得临界荷载的有限元解。利用FGM板的屈曲方程与参考均匀板的屈曲方程之间的相似性,建立了FGM板的临界荷载与参考均匀板的临界荷载之间的相似转换关系式,从而将FGM板临界荷载的计算转变为参考均匀板的临界荷载和材料不均匀系数的计算,极大地提高了计算效率,为FGM的推广起积极的推动作用。通过数值算例,将由有限元法和转换关系式得到的临界荷载进行了比较,并讨论了边界条件、荷载工况、材料组成和几何尺寸等对FGM板临界荷载的影响。     

Preparation of Cu（In,Ga）Se2 Thin Film Solar Cells by Selenization of Metallic Precursors in an Ar Atmosphere

Cu（In, Ga）Se2 thin films are deposited on Mo-coated glass substrates by Se vapour selenization of sputtered metallic precursors in the atmosphere of Ar gas flow under a pressure of about 10 Pa. The in situ heat treatment of as-grown precursor leads to the formation of a better alloy. During selenization, the growth of CuInSe2 phase preferably proceeds through Se-poor phases as CuSe and InSe at relatively low substrate temperature of 250℃, due to the absence of In2Se3 at intermediate stage at low reactor pressure. Subsequently, the Cu（In,Ga）Se2 phase is produced by the reactive diffusion of CuInSe2 with a Se-poor GaSe phase at high temperature of up to 560℃. The final film exhibits smooth surface and large grain size. The absorber is used to fabricate a glass/Mo/Cu（In, Ga）Se2/CdS/ZnO cell with the total-area efficiency of about 7%. The low open-circuit voltage value of the cell fabricated should result from the nonuniform distribution of In and Ga in the absorber, due to the diffusion-controlled reaction during the phase formation. The films, as well as devices, are characterized.     

Mo Back Contact for Flexible Polyimide Substrate Cu（In,Ga）Se2 Thin-Film Solar Cells

A dc magnetic sputtering process is applied to growth of a Mo back. contact layer onto the flexible polyimide （PI） and rigid soda-lime glass （SLC） substrates. The structural and electrical properties of the Mo layer coated on the two kinds of substrates are investigated by x-ray diffraction （XRD） and Hall effect measurements. The results show that the Mo layer on SLG indicate more better crystal quality and lower resistivity than that on the PI sheets. In contrast to the SLG substrate, the resistivity of the Mo layer on PI is increased by the vacuum annealing process at the substrate temperature of 450℃ under Se atmosphere, which is attributed to the cracked Mo layer induced by the mismatch of the coefficient of thermal expansion between PI and Mo material. The Cu（In,Ga）Se2 （CIGS） solar cells based on the PI and SLO substrates show the best conversion efficiencies of 8.16% and 10.98% （active area, 0.2cm^2）, respectively. The cell efficiency of flexible CIGS solar cells on PI is limited by its relatively lower fill factor caused by the Mo back contact.     

预制层溅射气压对CIGS薄膜结构及器件的影响

研究了金属预制层制备过程中溅射气压对Cu(In_1-xGa_x)Se₂(CIGS)薄膜及电池器件性能的影响.通过调节溅射气压改变预制层的结晶状态及疏松度与粗糙度,在合适的预制层结构下,活性硒化热处理过程中,可使Ga有效地掺入到薄膜中形成优质的CIGS固溶体.高溅射气压会使预制层过于致密,呈现非晶态趋势.经活性硒化热处理后,CIGS薄膜容易产生CIS与CGS"两相分离"现象,从而导致CIGS薄膜太阳电池的开路电压和填充因子降低,电池转换效率由10.03%降低到5.02%.