添加剂对基于PBDTC_(10)DBT∶PC_(61)BM光伏器件性能的影响

制备ITO/PEDOT∶PSS/PBDTC10BDT∶PC61BM/LiF/Al聚合物薄膜,研究了添加剂OT,DBrO对光敏层PBDTC10DBT∶PC61BM的影响,结果表明,加入微量的添加剂对光活化层的光吸收以及形貌起到积极的作用,添加剂的加入使得光活化层的分子排列更加有序,使各组分能够更好的吸收太阳光,同时光活化层的粗糙度减小,各组分之间的分布更加均匀,OT,DBrO的最佳添加量分别为2.5%和3%。当OT添加量为2.5%时,器件有最高光电转换效率1.93%。研究结果将为微相调节方法提高光伏器件性能提供理论依据和技术支持。     

Strategies for controlling the active layer morphologies in OPVs

This review focuses on the recent developments in our understanding of active layer morphologies for organic photovoltaic cells and approaches to obtain active layer morphologies for high power conversion efficiencies. The evolution of active layer morphologies, as studied by high resolution electron microscopy, X-ray and neutron scattering, and dynamic secondary ion mass spectrometry, is covered, along with strategies including the use of small molecule additives, polymer nanowires and polymer nanoparticles to realize active layer morphologies. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Modeling Photovoltaic Performances of BTBPD-PC61BM System via Density Functional Theory Calculations

Designing and fabricating high-performance photovoltaic devices have remained a major challenge in organic solar cell technologies.In this work,the photovoltaic performances of BTBPD-PC₆₁BM system were theoretically investigated by means of density functional theory calculations coupled with the Marcus charge transfer model in order to seek novel photovoltaic systems.Moreover,the hole-transfer properties of BTBPD thin-film were also studied by an amorphous cell with 100 BTBPD molecules.Results revealed that the BTBPDPC₆₁BM system possessed a middle-sized open-circuit voltage of 0.70 V,large short-circuit current density of 16.874 mA/cm²,large fill factor of 0.846,and high power conversion efficiency of 10%.With the Marcus model,the charge-dissociation rate constant was predicted to be as fast as 3.079×10¹³ s^-1 in the BTBPD-PC₆₁BM interface,which was as 3-5 orders of magnitude large as the decay (radiative and non-radiative) rate constant (10⁸-10¹⁰ s^-1),indicating very high charge-dissociation efficiency (～100%) in the BTBPD-PC₆₁BM system.Furthermore,by the molecular dynamics simulation,the hole mobility for BTBPD thin-film was predicted to be as high as 3.970×10^-3 cm²V^-1s^-1,which can be attributed to its tight packing in solid state.     

Bandgap Modulation in Efficient n‐Thiophene Absorbers for Dye Solar Cell Sensitization

Five new sensitizers for dye sensitized solar cells have been designed consisting of conjugated thienylenevinylene units threaded with alkyl chains to improve solubility and cyanoacetic acid as anchoring group. The conjugation length was increased from 2 to 6 thienylenevinylene units, which resulted in a red‐shift of the optical absorption of the dyes from 550 to 750 nm, improving the spectral overlap with the solar spectrum. The photovoltaic performance of these dyes as sensitizers in mesoporous TiO₂ solar cells shows a clear correlation of increasing photocurrent with the extension of the conjugation up to an optimal length. Further extension of the conjugation increases the absorption but additional effects like self‐quenching or recombination processes reduce the photocurrent and photovoltages and consequently the overall efficiency of the DSC.     

Modulation of optical and electronic properties of quinoxailine‐based conjugated polymers for organic photovoltaic cells

The synthesis of donor–acceptor type semiconducting copolymers is described. Quinoxaline (QX) or difluorinated quinoxaline (DFQX) derivatives serve as electron acceptors, while thiophene (T) or selenophene (Se) serve as electron donors. Alternating polymers are synthesized through Stille cross‐coupling, and their thermal stability, optical and electrochemical properties, field‐effect carrier mobilities, film crystallinities, and photovoltaic performances are investigated. The intramolecular charge transfer between the electron‐donating and electron‐accepting units in the backbone induces absorption from 450 to 750 nm. The optical band‐gap energies of the polymers are between 1.65 and 1.73 eV, and depend on the polymer structure. Organic photovoltaic cells fabricated using a polymer composed of DFQX and selenophene (PSe‐DFQX) exhibit a power conversion efficiency of 5.14% with an open‐circuit voltage of 0.78 V, a short‐circuit current density of 11.71 mA/cm², and fill factor of 0.57 under AM 1.5 G irradiation (100 mW cm^?2). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1904–1914     

基于BP神经网络和遗传算法的光伏功率预测的研究

随着光伏发电在社会的大规模应用,加之其波动性和间歇性等特点,使得光伏发电功率预测对微电网控制策略研究、电网电能调度和提高电网电能质量显得更加重要。遗传算法(GA)被运用来对建立的BP神经网络模型的初始权值和阈值进行优化,不仅加快了BP神经网络的收敛速度而且提高了BP神经网络的的预测准确度,实验结果显示采用的预测方法获得了较好的预测效果。     

Overcoming the thickness paradox: Systematical optimization of inverted polymer solar cells

Inverted structure comes out to be a promising alternative for making polymer solar cells (PSC) with high efficiency and long-term stability. Vertically stacked functional layers with planar shapes often suffer contradictions in holding high optical absorption and excellent charge transfer/hindrance capability to construct well performed inverted PSC devices. Here, we give an example of rational control of the thickness of electron transport layer (ETL), hole transport layer (HTL) and organic active layer (OAL) to achieve a synergistic effect on promoting the overall photovoltaic behaviors. With in-depth exploration of the interaction between device performance and layer thickness, we obtain the optimized device ITO/ZnO Ncs (45 nm)/P3HT:PCBM (70 nm)/MoO₃ (1 nm)/Ag (70 nm) exhibiting an V_oc of 0.63 V, J_sc of 12.52 mA/cm², FF of 54% and PCE of 4.26%.     

两级式光伏并网逆变器建模与非线性动力学行为研究

本文首先建立了两级式光伏并网逆变器严格的分段光滑状态方程, 分析级联情况下光伏阵列电压对光伏并网逆变器非线性动力学行为的影响, 然后探讨拓展两级式光伏并网逆变器输入电压范围的策略, 并研究前后级电路内部参数变化引起并网逆变器输出电流的快变尺度分岔和慢变尺度分岔现象. 研究发现: 若对光伏阵列电压进行分段控制, 可以有效展宽两级式光伏并网逆变器的输入电压范围; 适当增加前级输出电容值、电感量, 可以避免系统产生混沌运动, 而后级参数的取值需避开多个不连续的混沌区域. 研究结果对提高光伏发电系统的效率与稳定性有较重要的参考价值.     

单线态分裂的超快光谱学研究

有机分子中的单线态分裂过程能将单个光激发的单线态激子转化成两个三线态激子. 借助此载流子倍增效应, 太阳能电池可以更有效地利用太阳光谱中的高能光子, 进而突破单结太阳能电池效率的理论极限. 因此, 单线态分裂备受关注. 本文回顾学术界对单线态分裂物理图像的认识以及争议, 结合课题组近年来的一些结果, 重点总结此领域中运用瞬态光谱学方法取得的实验进展, 讨论有关多激子中间暗态机理的不同观点, 并介绍单线态分裂材料的发展以及器件应用.     

Textile‐Compatible Substrate Electrodes with Electrodeposited ZnO—A New Pathway to Textile‐Based Photovoltaics

A strategy is presented to realize textile‐based photovoltaic cells motivated by developments of textile‐based electronics and their demand of grid‐independent energy supply. Beyond this, a development of textile‐based photovoltaics also represents an attractive pathway towards very flexible and rugged solar cells. The need for compatibility of an appropriate photovoltaic technology with the physical limitations of textiles is stressed. Electrodeposition from aqueous solutions is presented as a successful strategy to realize semiconductor structures on textiles and detailed control and influence of the deposition conditions is discussed. The role of microelectrode effects, options of forced convection, deposition under pulsed potential, alternative deposition baths and different substrate metals are emphasized. An active electrode material is presented which reaches a conversion efficiency close to the 1 % limit under AM 1.5 illumination conditions and thereby opens the door for a further optimization towards devices of technical interest.