原子层沉积制备铱薄膜的特性研究

以乙酰丙酮铱[Ir(acac)3]和高纯氧为前驱体,采用原子层沉积(ALD)方法在基板温度为340℃的石英玻璃和硅基板上制备了金属铱薄膜。采用反射光谱测试仪、X射线电子能谱(XPS)、X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段对不同厚度薄膜的微结构、表面形貌和光学性能进行了研究。结果表明,原子层沉积制备的Ir薄膜中元素纯度较高(大于95%),表面粗糙度低,并呈现多晶纳米颗粒。同时,Ir薄膜在紫外波段表现出较好的光学特性,可以用于制作Ir金属紫外光栅等光学器件。     

基于多重自我假设的人质困境问题

囚徒困境及其变形模型,揭示了个体理性与群体理性选择之间的矛盾,从个体利益出发的行为往往不能实现团体的最大利益.本文以多重自我替代传统经济学中理性人的假设,将双曲贴现应用到人质困境中,解决短期利益与长期利益的不一致性给决策带来的困扰,从而实现个人利益与社会利益的统筹协调.     

Estimation of vector static magnetic field by a nitrogen-vacancy center with a single first-shell ~(13)C nuclear(NV–~(13)C)spin in diamond

We suggest an experimental scheme that a single nitrogen-vacancy(NV) center coupled to a nearest neighbor~(13) C nucleus as a sensor in diamond can be used to detect a static vector magnetic field. By means of optical detection magnetic resonance(ODMR) technique, both the strength and the direction of the vector field could be determined by relevant resonance frequencies of continuous wave(CW) and Ramsey spectrums. In addition, we give a method that determines the unique one of eight possible hyperfine tensors for an(NV–~(13) C) system. Finally, we propose an unambiguous method to exclude the symmetrical solution from eight possible vector fields, which correspond to nearly identical resonance frequencies due to their mirror symmetry about~(14)N–Vacancy–~(13) C(~(14)N–V–~(13) C) plane.     

Loss of cold atoms due to collisions with residual gases in free flight in a magneto-optical trap

The loss rate of cold atoms in a trap due to residual gas collisions differs from that in a free state after the cold atoms are released from the trap. In this paper, the loss rate in a cold rubidium-87 atom cloud was measured in a magneto-optical trap(MOT) and during its free flight. The residual gas pressure was analyzed by a residual gas analyzer, and the pressure distribution in a vacuum chamber was numerically calculated by the angular coefficient method. The decay factor, which describes the decay behavior of cold atoms due to residual gas collisions during a free flight, was calculated. It was found that the decay factor agrees well with theoretical predictions under various vacuum conditions.     

限制零点个数的亚纯函数的正规定则

设k,n(≥k+1)是两个正整数,a(≠0),b是两个有穷复数,F为区域D内的一族亚纯函数.如果对于任意的f∈F,f的零点重级大于等于k+1,并且在D内满足f+a[L(f)]~n-b至多有n-k-1个判别的零点,那么F在D内正规·这里L(f)=f~((k))(z)+a_1f~((k-1))(z)+…+a_(k-1)f'(z)+a_kf(z),其中a_1(z),a_2(z),…,a_k(z)是区域D上的全纯函数.     

多层金属纳米点阵的制备及其光学性质的研究

采用纳米球刻蚀法结合热蒸发技术制备了银和氧化硅交替层叠的纳米颗粒阵列. 扫描隧道显微镜测量结果表明, 该纳米阵列呈锥形多层结构. 分光光度计测量样品表明, 该纳米阵列在近红外波段存在明显的透射谷, 该透射谷来源于金属纳米颗粒局域等离激元的激发, 随着金属/介质层数的增多, 透射谷的位置向短波方向移动. 利用HFSS软件对该纳米阵列进行了仿真, 并分析了透射谷蓝移的原因. 关键词： 纳米球刻蚀技术 金属/介质纳米颗粒 表面等离子激元     

双量子阱中光子辅助电子自旋隧穿

采用单电子有效质量近似理论, Floquet理论和传递矩阵方法, 对包含时间周期场的双量子阱中单电子的自旋隧穿特性进行了研究, 对InP/InAs半导体材料进行了数值计算. 重点研究了Rashba型和Dresselhaus型自旋轨道耦合、量子阱结构以及偏压对电子隧穿的影响. 这些结果可以为设计和调控半导体自旋电子器件提供一定的理论依据. 关键词： 光子辅助隧穿 隧穿概率 量子阱     

Cu2O-ZnO异质结太阳能电池的制备及光电性能研究（英文）

电化学沉积是一种绿色高效的材料制备方法。本实验使用电化学沉积法分别制备了单晶的氧化锌(ZnO)纳米棒阵列和p型的氧化亚铜(Cu2O)薄膜,并对样品进行了扫描电镜、X光衍射、外量子效率和光电性能测试等一系列的表征和测试。试验结果表明,通过改变反应溶液中的ZnCl2浓度可以来调控ZnO纳米棒的直径。光电性能测量显示在Cu2O/ZnO间形成了p-n异质结。量子效率的测试证明该异质结可有效地促进载流子的分离和传送,从而提高太阳能电池的转化效率。