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.     

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.     

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.     

Raman scattering of polycrystalline GaSb thin films grownby co-evapouration process

<正>This paper reports that GaSb thin films have been co-deposited on soda-lime glass substrates.The GaSb thin film structural properties are characterized by Raman spectroscopy.The Sb-A_1g/GaSb-TO ratio decreases rapidly with the increase of substrate temperature,which suggests a small amount of crystalline Sb in the GaSb thin film and suggests that Sb atoms in the thin film decrease.In Raman spectra,the transverse optical（TO） mode intensity is stronger than that of the longitudinal optical（LO） mode,which indicates that all the samples are disordered.The LO/TO intensity ratio increases with increasing substrate temperature which suggests the improved polycrystalline quality of the GaSb thin film.A downshift of the TO and LO frequencies of the polycrystalline GaSb thin film to single crystalline bulk GaSb Raman spectra is also observed.The uniaxial stress in GaSb thin film is calculated and the value is around 1.0 GPa.The uniaxial stress decreases with increasing substrate temperature.These results suggest that a higher substrate temperature is beneficial in relaxing the stress in GaSb thin film.     

吸收层成份比例对CIGS太阳电池性能的影响

本文利用传统的共蒸发三步法制备了CIGS薄膜及电池器件,通过X射线荧光光谱仪(XRF)、扫描电镜(SEM)、Hall测试仪、太阳光模拟器I-V曲线测试等方法,研究了Cu和Ga元素比例的不同对电池二极管特性及效率的影响,获得了Cu/(In+ Ga)比值为0.89～0.93、Ga/(In+ Ga)比值为0.29～ 0.33是制备高效电池的理想范围的结论,并分析了偏离理想成份范围的电池性能下降的原因.最后通过工艺优化,制备出理想成份范围内的高质量CIGS薄膜,获得了15.27;的高转换效率电池.     

Cu(In,Ga)Se2薄膜太阳电池二极管特性的研究

本文采用线性拟合光态和暗态J-V(电流-电压)曲线的方法计算了不同效率的Cu(In,Ga)Se2(CIGS)薄膜太阳电池的二极管性能参数.在一定范围内,CIGS薄膜电池的二极管品质因子A和反向饱和电流J0值越小,电池的转换效率越高,这说明CIGS电池的复合主要发生在PN结区内.量子效率分析表明,不同效率的CIGS电池在短波区(λ<520 nm)的光谱响应相差不大,而在长波区(520～1100 nm),低效率电池存在很大的吸收,这是由低质量的CIGS吸收层造成的.这进一步验证了光-暗态J-V曲线的分析结果,即高质量的吸收层是制备CIGS电池的关键.     

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.     

P型微晶硅薄膜材料性能的研究

本文讨论了P型微晶硅薄膜性能随硅烷浓度(SC)的变化.采用X射线衍射仪(XRD),拉曼光谱仪和傅立叶变换红外吸收光谱仪(FTIR)对薄膜的结构进行了表征.随硅烷浓度的增加,微晶硅薄膜材料的生长速率和暗电导率(σd)逐渐增大,光学带隙逐渐降低.当硅烷浓度为2.0;时,硅基薄膜材料是以非晶硅为主并有散落的微晶硅颗粒的非晶硅结构.当硅烷浓度为1.5;时,硼的掺杂效率最大,同时可观察到硼抑制薄膜晶化的现象.     

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.