低温生长Cu(InGa)Se2薄膜吸收层的掺钠工艺研究

在柔性聚酰亚胺衬底上低温制备Cu(In,Ga)Se₂薄膜太阳能电池, Na的掺入会改善电池特性, 但不同的掺Na工艺对Cu(In,Ga)Se₂薄膜和器件特性的改善机理不同. 本实验通过对比前掺NaF和后掺NaF工艺发现, 在前掺Na工艺下, 由于Na始终存在于Cu(In,Ga)Se₂薄膜生长过程中, Na存在于多晶 Cu(In,Ga)Se₂ 薄膜晶界处, 起到了扩散势垒的作用, 导致晶粒细碎、加剧两相分离, 同时减小了施主缺陷的形成概率; 而在后掺Na工艺下, 掺入的Na对薄膜的结构及生长不产生影响, 仅仅起到了钝化施主缺陷、改善薄膜缺陷态的作用. 同时, 研究表明, 后掺Na工艺中, NaF必须依靠外界能量辅助才能扩散进Cu(In,Ga)Se₂内部, 实验结果证实, 只有衬底温度达到350 ℃以上时, 掺入的NaF才能较好地改善薄膜特性. 最终经掺Na工艺的优化, 得到低温工艺制备的柔性聚酰亚胺衬底器件效率达10.4%.     

A RECURSION THEORY STUDY OF THE ELECTRONIC STRUCTURE OF METALLIC SUPERLATTICES

We illustrate that the recursion method is useful in the study of the electronic structure of metallic superlattices.It reduces considerably the amount of computational works,and gives,nevertheless,fairly satisfactory densities of states.     

感应耦合等离子体中原子发射光谱的非局部热平衡 Ⅰ.非玻尔兹曼分布

本文叙述了在感应耦合等离子体中,原子激发过程可以用台阶式模型来近似,从而证实了激发态粒子数的局部非玻尔兹曼分布是等离子体光学薄性质的必然结果。从理论上讨论了局部非玻尔兹曼分布公式以及分布曲线弯曲时的拐点能量。     

Amplification of spontaneous emission in Nd~(3 )-doped fiber pumped by Ti: Al_2O_3 tunable laser

Amplification of spontaneous emission(ASE) in 4m Nd~(3 )-doped fiber pumped by Ti : Al~2O_3 tunable laser is studied theoretically and experimentally. The output of 2.64mW from ASE source pumped at 833 nm is obtained and the experimental results of ASE source are compared with that of Nd~(3 )-doped fiber ring laser.     

α—萘酚胁迫对普通小球藻生长及抗氧化酶活性的影响

研究了α－萘酚对普通小球藻的生长、光合色素的MDA含量及抗氧化酶9SOD、CAT、POD）活性的影响,结果表明,随着α－萘酚浓度的升高,藻的生长速率、叶绿素a与类胡萝卡素的含量,SOD、CAT、POD活性均先升高后下降,除POD活性在5．00mg.L^－1时达到最大值外,其余均在2．00mg.L^-1达到最大,而在α－萘酚浓度低于2．00mg.L^-1时,MDA含量变化不大,只有当3种抗氧化酶活性呈不同的下降后,MDA含量才急剧上升,膜脂过氧化加剧,说明α－萘酚导致普通小球藻膜脂过氧化是其致毒机制之一,而抗氧化酶在一定污染物浓度范围内具有防御保护作用。     

Threshold gain behavior of lasing modes in two-dimensional active random media

The pumping rate dependence of the peak intensity of the individual lasing mode in two-dimensional (2D) active random media is investigated. The results show that these modes have a typical threshold gain behavior and different threshold pumping rates. There exists a certain correspondence between the mode's threshold pumping rate and its lifetime, and the longer the lifetime is, the lower the threshold is.     

六方相TbPO_4·nH_2O的控制合成及发光性能研究

通过控制PO3-4/Tb3+的量比,在低温水热条件下合成了不同形貌的TbPO4·nH2O纳米晶体。采用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)及光致发光光谱(PL)等分析手段对所制备的样品进行了表征。研究了溶液中PO3-4/Tb3+比值变化对产物晶型结构、形貌、晶粒尺寸及发光性能的影响,给出了TbPO4·nH2O纳米粉体的生长机理。实验发现,当PO3-4/Tb3+比值达到60∶1时,产物在过量的磷酸根体系中生长成直径为100~200 nm的TbPO4·nH2O茧状微球,且产物的发光强度最大。PO3-4/Tb3+比值对TbPO4·nH2O形貌和发光性能有重要影响。     

红外低温相机视轴引出方法

测量红外低温相机的系统调制传递函数(MTF)需要借助于低温平行光管。由于红外低温相机探测器在常温下无法正常工作,并且红外低温相机、低温平行光管离轴抛物镜以及模拟靶标三者是空间分离的,因此实验前需要将相机的视轴引出到平行光管的视轴方向,同时将模拟靶标调整到平行光管焦面位置且靶标中心处于平行光管的中心视场。借助于干涉仪,利用经纬仪分别将相机视轴和平行光管视轴引出到外基准立方镜a和b,通过两立方镜坐标系的方向余弦矩阵关系,将红外低温相机的视轴引出到低温平行光管的视轴方向。对视轴引出精度进行了分析,给出了实验采集的图像。实验结果表明,系统MTF满足要求,同时表明红外低温相机视轴引出方法合理可行。     

Photoinduced charge injection in the metal/organic interface studied by transient photovoltage measurements with bias

Transient photovoltage of ITO/organic/Al cells is studied under different bias polarities and voltages.It is found that for an ITO/NPB/Al cell,light incidence on the Al side induces more bias-dependent transient photovoltage variation when the photovoltage is positive than when it is negative.However,for an ITO/C60 /Al cell,the variation characteristics of transient photovoltage is reversed.These results support the previously proposed mechanism that Al could inject charges into the organic layer upon photon excitation,indicating that the absorption of electrode can also contribute to photovoltaic effect.