ELECTRONIC-STRUCTURES OF THE ALKALI-CONTAINING BUCKMINSTERFULLERENES (A-DELTA-C60) (A=LI,NA,K,RB,CS) AND THE HALOGEN-CONTAINING BUCKMINSTERFULLERENES (H-DELTA-C60) (H=F,CL,BR,I)

The geometrical parameters and electronic structures of C60, (A partial derivative C60) (A = Li, Na, K, Rb, Cs) and (H partial derivative C60) (H = F, Cl, Br, I) have been calculated by the EHMO/ASED (atom superposition and electron delocalization) method. When putting a central atom into the C60 cage, the frontier and subfrontier orbitals of (A partial derivative C60) (A = Li, Na, K, Rb, Cs) and (H partial derivative C60) (H = F, Cl) relative to those of C60 undergo little change and thus, from the viewpoint of charge transfer, A (A = Li, Na, K, Rb, Cs) and H (H = F, Cl) are simply electron donors and acceptors for the C60 cage resPeCtively. Br is an electron acceptor but it does influence the frontier and subfrontier MOs for the C60 cage, and although there is no charge transfer between I and the C60 cage, the frontier and subfrontier MOs for the C60 cage are obviously influenced by I. The stabilities DELTAE(X) (DELTAE(X) = (E(X) + E(C60)) - E(x partial derivative C60)) follow the sequence I < Br < None < Cl < F < Li < Na < K < Rb < Cs while the cage radii r follow the inverse sequence. The stability order and the cage radii order have been explained by means of the (exp-6-1) potential.

GaAs基MOEMS波长可调谐滤波器的设计和理论模拟

采用传输矩阵理论和结合悬臂梁的电学一机械模型对GaAs基1.55 μm微光电机械系统(MOEMS)波长可调谐滤波器的光学和电学特性进行了深入的对比分析和研究.结果表明,采用800 nm厚的空气腔可以实现滤波器波长的调谐范围为100 nm,所需最大反向偏压为4 V,波长的调谐速率可以达到1.83 MHZ.

霍尔罗盘误差补偿算法及实验分析

研究了锑化铟(InSb)霍尔罗盘中的椭圆误差补偿问题。文中详细分析了基于椭圆假设的罗盘误差补偿算法,使罗盘具备了自动误差补偿和自动校准功能。实验结果表明,利用这种算法的霍尔罗盘精度达到了±2.46°,基本达到了实用要求。本文还详细分析了影响罗盘精度的原因和以后改进的措施.

纳米非晶硅(na-Si:H)P-i-n太阳电池

该文报道了通过适当氢稀释(RH=15)和合适的衬底温度(Ts=170℃)下,用PECVD制备得到的宽带隙氢化纳米非晶硅(na-Si:H)薄膜,并将其用作pin太阳电池的本征层.经过电池结构和工艺条件的优化设计,在p/i,i/n界面插入渐变带隙缓冲层,制备出了glass/ITO/p-a-SiC:H/i-na-Si:H/n-nc-Si:H/Al结构的pin太阳电池.电池初始开路电压(Voc)高达0.94V,同时还能保证0.72的填充因子(FF).光电转换效率(Eff)达到8.35%(AM1.5,100mW/cm2).

微光成像系统信噪比及图像探测特性研究

分析了电子轰击电荷耦合器件(EBCCD)微光成像系统的噪声源,建立了系统的信噪比模型,指出了在微光成像系统本身的增益和量子效率等性能确定的条件下,成像系统输出图像信噪比不仅仅与输入面照度有关,还与输入图像的空间频率有关,并通过实验得到了证明,指出了经典的图像探测方程(Rose方程)的不完善之处.

多壁碳纳米管的拉曼散射

报导了用直流碳弧放电方法制备的多层碳纳米管的喇曼光谱。其红移范围分布在2 cm~(-1)～13 cm~(-1)范围内。

In_(1-x-y)Ga_xAl_yAs四元混晶的喇曼散射

国家自然科学基金