负偏压作用下染料敏化太阳电池界面及光电性能研究

太阳电池组件由于局部电压不匹配,其中部分电池可能较长时间工作在负偏压状态下,从而影响电池光电性能.借助拉曼光谱、电化学阻抗谱和入射单色光量子效率(IPCE)等测试手段,研究长期负偏压作用下染料敏化太阳电池光电性能的变化及其影响机理.拉曼光谱研究结果表明:电池在1000 h负偏压作用下,电解质中阳离子(Li⁺)会向光阳极(TiO₂电极)移动并嵌入TiO₂薄膜中;长期负偏压作用还会致使TiO₂/电解质界面阻抗增大和IPCE下降,导致电池开路电压升高和短路电流减小.通过加入苯并咪唑(BI)添加剂,经1000 h负偏压后电池的拉曼光谱实验表明,BI能在一定程度阻碍Li⁺的嵌入,电池具有较好的长期稳定性.不同负偏压下的老化实验进一步表明,通过加入添加剂能够使电池在长期负偏压下保持较好的稳定性. 关键词： 染料敏化 太阳电池 组件 负偏压     

Long-time limit behavior of the solution to an atom’s master equation

We study the long-time limit behavior of the solution to an atom’s master equation.For the first time we derive that the probability of the atom being in the α-th(α = j + 1-j z,j is the angular momentum quantum number,j z is the z-component of angular momentum) state is {(1- K/G)/[1-(K/G) 2j+1 ]}(K/G) α-1 as t → +∞,which coincides with the fact that when K/G > 1,the larger the α is,the larger the probability of the atom being in the α-th state(the lower excited state) is.We also consider the case for some possible generalizations of the atomic master equation.     

Multi-Partite EPR Entangled State Representation for Continuous Variables and Its Application in Squeezing Theory

By extending the Einstein-Podolsky-Rosen (EPR) bipartite entanglement to an n-partite case, we construct the common eigenstate of the n-partite total coordinate and relative momenta for the continuous variables. The entanglement property of the state is shown. The classical dilation transform of variables in such a state induces a new n-mode squeezing operator related to an n-mode bosonic operator realization of SU(1,1) Lie algebra.     

Energy average formula of photon gas rederived by using the generalised Hermann-Feynman theorem

By virtue of the generalised Hermann-Feynmam theorem we re-derive the energy average formula of photon gas. This is another useful application of the theorem.     

大面积染料敏化太阳电池的串联阻抗特性研究

在电子扩散微分方程的基础上,研究了染料敏化太阳电池光生电流和光生电压随光照强度不同的变化关系.提出敏化太阳电池串联阻抗功率损耗模型,理论模拟了大面积电池（有效面积>1 cm²）光电转换效率随多孔薄膜有效面积宽度变化的曲线、透明导电基底膜与银栅极的比接触电阻以及在不同入射光强下银栅极体电阻对大面积染料敏化太阳电池光伏性能的影响.结果表明透明导电基底膜的方块电阻和银栅极体电阻对大面积染料敏化太阳电池的性能有很大影响,而这种影响随光强的减弱逐渐减小. 关键词： 染料敏化 太阳电池 串联阻抗 光电转换效率     

Operator Formulas Involving Generalized Stirling Number Derived by Virtue of Normal Ordering of Vacuum Projector

By virtue of the normal ordering of vacuum projector we directly derive some new complicated operator identities, regarding to the generalized Stirling number.     

One-Step Generation of Multi-Qubit GHZ and W States in Superconducting Transmon Qubit System

We propose a one-step method to prepare multi-qubit GHZ and W states with transmon qubits capacitively coupled to a superconducting transmission line resonator(TLR).Compared with the scheme firstly introduced by Wang et al.[Phys.Rev.B 81(2010) 104524],our schemes have longer dephasing time and much shorter operation time because the transmon qubits we used are not only more robust to the decoherence and the unavoidable parameter variations,but also have much stronger coupling constant with TLR.Based on the favourable properties of transmons and TLR,our method is more feasible in experiment.     

Evolution of a two-mode squeezed vacuum in the amplitude dissipative channel

For the first time we derive the dissipating result of an initial two-mode squeezed pure vacuum state passing through a two-mode amplitude dissipative channel described by the direct product of two independent single-mode master equations. Although these two master equations do not mix the two modes (there is no coupling between them), since the two-mode squeezed state is simultaneously an entangled state, the final state which emerges from passing this channel is a two-mode mixed density operator. The compact expression of the outcoming state is obtained, which manifestly shows that as time evolves, the squeezing effect decreases.     

Two mutually conjugated tripartite entangled states and their fractional Fourier transformation kernel

We newly construct two mutually-conjugate tripartite entangled state representations,based on which we propose the formulation of three-mode entangled fractional Fourier transformation(EFFT) and derive the transformation kernel.The EFFT’s additivity property is proved and the eigenmode of EFFT is derived.As an application,we calculate the EFFT of the three-mode squeezed vacuum state.     

电路QED系统实现超导电荷量子位的隐形传态

利用超导电荷量子位与传输线共振器(TLR)的电容耦合,提出一个简单的隐形传态的方案。该方案成功传送的概率为1,而且不受传输线共振器的影响。