有机太阳能电池研究进展

为了减轻当前能源危机所带来的压力,各国在太阳能电池等清洁能源领域投入了大量的人力、物力和财力.由于有机太阳能电池具有独特的优点(有机材料易于修饰,器件制备方法简便且可制备出柔韧器件),并且随着相关研究的深入,有机太阳能电池的能量转换效率逐步得到提高,这昭示了有机太阳能电池商业化的美好前景,目前已经有大批科研工作者投身于有机太阳能电池领域的研发工作.文章从太阳能电池小分子材料、聚合物材料和提高有机太阳能电池能量转换效率的方法这三方面入手,对有机太阳能电池领域进行综述.     

有机太阳能电池的工作原理及应用前景展望

有机太阳能电池的制备工艺简单、能耗少、柔性可卷曲、制造成本较低,具有广阔的应用前景,因此对有机太阳能电池研究,一直是国际上的学术热点.本文从有机太阳能电池的结构、工作原理、应用前景展望等方面对有机太阳能电池进行了简要的介绍,希望对物理同仁、中学生了解前沿科技有所帮助.     

溶液法制备全无机钙钛矿太阳能电池的研究进展

太阳能光伏技术,能实现太阳能与电能的高效转换,是实现人类文明可持续发展的关键绿色能源技术.其中,有机无机杂化钙钛矿太阳能电池具有优异的光电特性、低廉的制备成本、高效的转换效率,已成为该领域的研究前沿.虽然有机无机杂化钙钛矿太阳能电池的光电转换效率已约高达24%,但其体系中的有机物组分易受环境中的光、热、潮等因素影响而分解,致使器件稳定性存在严重的缺陷,极大地限制了钙钛矿太阳能电池的产业化进程.因此,如何制备高效稳定的钙钛矿太阳能电池,是目前该领域的研究热点与难点,而发展具有更高环境稳定性的全无机钙钛矿太阳能电池具有重要意义.本文回顾了近年来全无机钙钛矿太阳能电池领域的研究成果,重点审视了钙钛矿薄膜的湿法制备工艺,并探讨了器件在光热稳定性方面的改善,为进一步推动钙钛矿太阳能电池的实用化进程提供可行性参考.     

新型高效太阳能电池研究进展

第三代太阳能电池以超高效率、薄膜化、低成本为主要目标,目前发展起来的有多结叠层太阳能电池、中间带太阳能电池、多激子产生太阳能电池、热载流子太阳能电池和热光伏太阳能电池等.文章简要介绍了以上几种新型太阳能电池的工作原理和最新进展,并对其发展前景作了分析和预测.     

有机太阳能电池能量转化效率的提高思路

能源问题是目前最为关注的焦点之一,随着社会的进步和工业的发展,地球上已探明可使用的化学燃料能源,包括石油、天然气和煤等,日趋枯竭.太阳能的利用已引起各国的重视.光伏器件是太阳能利用的最为重要的手段之一,有机太阳电池在此类器件中将承担极其重要的角色.但低的光电转换效率是阻碍其产业化的瓶颈.为此简要综述了提高有机太阳能电池...     

材料设计以及界面与器件工程最适化以实现高性能聚合物和钙钛矿太阳能电池

有机聚合物和钙钛矿杂化物在合成控制、加工及属性调控的进展显著地增强了其太阳能电池性能。聚合物和杂化太阳能电池的性能十分依赖材料吸收光子、激子离解、电荷传输以及在金属/有机/金属氧化物或金属/钙钛矿/金属氧化物界面的电荷收集的效率。介绍了如何通过有效地整合材料设计以及界面与器件工程以显著提高聚合物和杂化钙钛矿型太阳能电池性能(转换效率>18%)。还介绍了一些关于制备串联和半透明太阳能电池的新型器件结构和光学工程策略,以发挥聚合物和钙钛矿太阳能电池的最大潜能。     

异质结及其技术在新型硅基太阳能电池中的应用

文章综述了异质结及其技术在新型硅基太阳能电池中的应用.从太阳能电池特性角度,点评了其在晶体硅、非晶硅薄膜太阳能电池及新结构太阳能电池应用中的研究热点和研究现状.在此基础上,讨论了其在不断与晶体硅、薄膜硅太阳能电池融合中的发展动态.     

使用不同阴极缓冲层提升性能的反型有机太阳能电池

使用含Al_q3、Bphen、BCP、HATNA和Cs₂CO₃作为阴极缓冲层,制备了基于SubPc和C₆₀的反型平面异质结有机太阳能电池. 比较了有机阴极缓冲层的最低未占有分子轨道和电子迁移率对有机太阳能电池性能的影响. 结果显示,Al_q3、Bphen和HATNA能够大幅度提升器件的性能. 使用退火过后的HATNA作为阴极缓冲层获得了最高的效率,比没有阴极缓冲层的器件提升了7倍. 另外,使用空间电荷限制电流理论进行仿真的结果表明,通过加入HATNA作阴极缓冲层,反型有机太阳能电池结构中处于有机/电极界面处的肖特基势垒降低了27%.     

一种新方法制备硅/聚(3, 4-乙撑二氧噻吩)核/壳纳米线阵列杂化太阳能电池

采用气相聚合法制备了有机/无机杂化的硅/聚3, 4-乙撑二氧噻吩核/壳纳米线阵列(SiNWs/PEDOT)太阳能电池. 相对平面结构Si/PEDOT太阳能电池, SiNWs/PEDOT太阳能电池的能量转换效率提升了7倍, 达到3.23%.对比分析反射光谱、I-V曲线及外量子效率的实验结果, 发现SiNWs/PEDOT太阳能电池性能改进的主要原因可归结为: 气相聚合法能够有效地制备出SiNWs/PEDOT电池的核/壳纳米线阵列结构, 使得器件具有高光捕获、高比结面积和高电荷收集效率. 关键词： Si/PEDOT核/壳纳米线结构 太阳能电池 气相聚合     

基于三元非富勒烯体系的高效有机太阳能电池

有机材料的"窄吸收"特性制约了有机太阳能电池(OPVs)性能的进一步突破,二元体异质结薄膜难以实现对太阳能的有效宽光谱利用.三元OPVs在二元体系中引入吸收互补的第三组分,能够增强器件光吸收,实现光电转化效率的大幅提升.近年来,非富勒烯受体材料的飞速进展,多次刷新有机太阳能电池最高效率记录,丰富并扩展了三元受体材料的选择范围.本文以非富勒烯受体材料Y6作为第三组分材料,高效率非富勒烯太阳能电池PBDB-T-2F:IT-4F作为基础二元器件,研究并分析了以双非富勒烯材料为受体的三元有机太阳能电池工作机理.通过光电特性分析,发现Y6的引入不仅能够增强器件近红外区域的光吸收能力,而且能够有效抑制双分子复合,提高电荷取出率,从而提高器件能量转换效率.通过调节Y6在三元体系中的质量百分比,在Y6占比为20 wt%时,器件实现最高的能量转换效率12.48%,相比于基础二元器件(10.59%)实现了17.85%的性能提升.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Research on beamforming method for dual-line array with space mismatch between the two line arrays

The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.