聚3-己基噻吩：非富勒烯太阳能电池中的量子效率损失和电压损失

聚3-己基噻吩(P3HT)以其合成工艺简单、成本低廉的优势,成为有机光伏领域中最具吸引力的电子给体材料之一。然而,目前P3HT: 非富勒烯太阳能电池的光伏性能仍然较差。在本工作中,我们证明了与P3HT: 富勒烯太阳能电池相比,较快的电荷转移态的非辐射衰减速率(K_nr)是导致P3HT: 非富勒烯太阳能电池中较低的量子效率和较高的电压损失的原因。然后,我们研究了基于非富勒烯受体ZY-4Cl的太阳能电池的工作机理。研究结果表明与P3HT: 非富勒烯体系相比,P3HT: ZY-4Cl中K_nr的降低改善了器件的量子效率,同时降低了电压损失。K_nr降低的原因可以部分归因于电荷转移态能量的增加。此外,给体分子和受体分子之间的距离(DA间距)的增大也是K_nr减少的重要原因。因此,我们得出结论：为了提高P3HT太阳能电池的性能,需进一步降低器件的K_nr,这可通过增加活性层中的DA间距来实现。     

煤介质损失角正切的分形特征

利用分形几何理论对煤的介质损失角正切的特征作了深入的探讨·结果表明,煤的介质损失角正切tgδ具有分形特征;通过类比和实验证实的方法得到了tgδ与f间的定量关系：tgδf(D-d)/2,借此求得了煤分形介质损失角正切维数。     

昌邑市质监局一次检查为企业挽回巨额损失

一般来说，企业对进厂现场检查的执法行为总有怨言，认为检查就是为了收费，检查不出个所以然来，企业对检查很不配合。但近日，昌邑市质监局组织的一次检查，却彻底改变了企业对质检局的看法。     

稀土金属在氯化物熔体中溶解损失的研究

目前,工业上广泛采用氯化物体系熔盐电解法制取稀土金属,但电流效率低,一般只有40％左右。稀土金属在熔盐中的溶解损失是电流效率低的重要原因之一,关于这方面的研究虽有些报道,但多限于单一稀土金属在自身熔盐中的溶解。在文献的基础上,我们进一步研究了混合稀土金属(RE)在RECl_3-KCl熔体中的溶解损失及LiCl、NaCl、     

测定镍硼合金时硼损失的探讨

用硝酸、盐酸混合酸分解镍硼中间合金、硫代硫酸钠-氢氧化钠容量法滴定硼时,其测定结果往往因硼有损失而偏低。近年来,我们对偏低的原因作了探讨,发现主要是两方面的原因:一是试样分解不完全;另一原因是在试样分解过程中或者分解完全之后,硼的状态发生了变化。本文拟定了硼的分析方法,并对结果偏低的原因及解决办法提出一些粗浅看法。     

酚醛树脂热裂解碳阳极的不可逆容量损失

用酚醛树脂热裂解得到的无序碳为阳极研究了在第一次循环时不可逆容量损失的原因。实验结果表明，不可逆容量损失是由于溶剂分解产生了Li2CO3和在碳表面上形成了含-COO^-基和C-H基的化合物以及在碳主体上形成了含-OLi,-CLi化合物所致。     

单体固体氧化物电解池极化损失分析及阴极微结构优化

基于高温固体氧化物电解池(SOEC)的高温蒸汽电解(HTSE)制氢技术作为一种非常有前景的大规模核能制氢新方法, 受到国际上的迅速关注. 但如何控制电解模式下的极化能量损失和性能衰减是HTSE实用化的关键. 本文通过在线电化学阻抗测试技术, 研究了实际运行状态下的单体固体氧化物池(SOC)在电池模式和电解模式下的极化阻抗分布, 阐述了SOEC与高温固体氧化物燃料电池(SOFC)的差异, 确定了SOEC氢电极支撑层水蒸气扩散过程极化损失大是制约电解池制氢性能提高的主要因素. 在此基础上, 采用聚甲基丙烯酸甲酯(PMMA)造孔剂对氢电极支撑层的微观结构进行了调整和优化. 微结构优化后, 氢电极材料的孔隙率提高了50%, 孔隙为规则圆形, 分布均匀, 更利于气体扩散; 电解电压1.3 V时, 单位面积产氢率高达328.1 mL·cm^-2·h^-1(标准态), 为改进前电解池的2倍, 实现50 h以上连续稳定性运行. 研究成果可为HTSE的实际应用提供一定的理论数据和技术基础.     

降低非富勒烯有机太阳能电池能量损失的机制和策略

在过去20年，溶液加工制备本体异质结有机太阳能电池（BHJ-OSCs）发展迅速，其能量转换效率（PCE）已经超过19%，但器件的能量损失（Eloss）相对较大，成为限制其光伏性能的瓶颈因素。因此，通过降低能量损失进一步提高OSCs的PCE成为该领域的研究重点。通过对OSCs中光物理过程的分析，讨论了不同能量损失途径的机理，综述了以下四种策略：（1）减小给受体间的能级差，（2）降低能量无序度，（3）提高器件的发光效率，（4）减小重组能。本文系统总结了降低非富勒烯OSCs体系Eloss的最新进展，为进一步提高该类器件性能提供重要参考。     

铈在NaCl-KCl和NaCl-KCl-CeCl_3体系中溶解损失研究

在实验室条件下,利用差重分析法,研究了Ce在Na Cl-KCl和Na Cl-KCl-Ce Cl3体系中的溶解损失,观察了Ce的物理溶解现象。利用二次回归正交分析,得到了Ce溶解损失量与温度和Ce Cl3浓度之间的数学模型,绘制了各因素与溶解损失之间的关系曲线,讨论了金属溶解损失随时间、温度和Ce Cl3浓度的变化规律。研究表明,Ce在Na Cl-KCl体系的溶解损失量随温度增加而增加,达到平衡前随时间增加而增加,达到平衡后不再随时间变化;在Na Cl-KCl-Ce Cl3体系的溶解损失量随Ce Cl3浓度增加而增加,随温度的变化存在拐点。     

A chlorinated non-fullerene acceptor for efficient polymer solar cells

After additive and thermal annealing treatment, the PM6:Y15 based device obtains a high power conversion efficiency of 14.13%.     

A non-fullerene acceptor enables efficient P3HT-based organic solar cells with small voltage loss and thickness insensitivity

The large D core of DFPCBR results in efficient P3HT-based OSCs with a high V_OC and thickness insensitivity.     

基于一种新型聚噻吩衍生物为给体的非富勒烯聚合物太阳能电池

With the development of non-fullerene small-molecule acceptors, non-fullerene polymer solar cells (PSCs) have garnered increased attention due to their high performance. While photons are absorbed and converted to free charge carriers in the active layer, the donor and acceptor materials both play a critical role in determining the performance of PSCs. Among the various conjugated-polymer donor materials, polythiophene (PT) derivatives such as poly(3-hexylthiophene), have attracted considerable interest due to their high hole mobility and simple synthesis. However, there are limited studies on the applications of PT derivatives in non-fullerene PSCs. Fabrication of highly efficient non-fullerene PSCs utilizing PT derivatives as the donor is a challenging topic. In this study, a new PT derivative, poly[5, 5′-4, 4′-bis(2-butyloctylsulphanyl)-2, 2′-bithiophene-alt-5, 5′-4, 4′-difluoro-2, 2′-bithiophene] (PBSBT-2F), with alkylthio groups and fluorination was synthesized for use as the donor in non-fullerene PSC applications. The absorption spectra, electrochemical properties, molecular packing, and photovoltaic properties of PBSBT-2F were investigated and compared with those of poly(3-hexylthiophene) (P3HT). The polymer exhibited a wide bandgap of 1.82 eV, a deep highest occupied molecular orbital (HOMO) of -5.02 eV, and an ordered molecular packing structure. Following this observation, PSCs based on a blend of PBSBT-2F as the donor and 3, 9-bis(2-methylene-(3-(1, 1-dicyanomethylene)-indanone)-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno-[2, 3-d:2′, 3′-d′]-s-indaceno[1, 2-b:5, 6-b′]dithiophene (ITIC) as the acceptor were fabricated. The absorption spectra were collected and the energy levels were found to be well matched. These devices exhibited a power conversion efficiency (PCE) of 6.7% with an open-circuit voltage (V_OC) of 0.75 V, a short-circuit current density (J_SC) of 13.5 mA·cm^-2, and a fill factor (FF) of 66.6%. These properties were superior to those of P3HT (1.2%) under the optimal conditions. This result indicates that PBSBT-2F is a promising donor material for non-fullerene PSCs.     

D-A Copolymers Based on a Pentacyclic Acceptor Unit and a 3,3′-Difluoro-2,2′-bithiophene for Solar Cells

A D-A copolymer, P2FBTTPTI, was developed by copolymerizing a pentacyclic acceptor unit, thieno[2′,3′:5,6]pyrido[3,4-g]thieno[3,2-c]isoquinoline-5,11(4 H,10 H)-dione(TPTI), with 3,3′-difluoro-2,2′-bithiophene(2 FBT). P2 FBTTPTI possessed a low highest occupied molecular orbital(HOMO) energy level(-5.50 e V) and a good hole mobility(4.14 × 10~(-4) cm~2·V~(-1)·s~(-1)). P2FBTTPTI:PC_(71)BM solar cells gave a decent power conversion efficiency(PCE) of 7.64% and a high open-circuit voltage(V_(oc)) of 0.95 V.     

Combining chlorination and sulfuration strategies for high-performance all-small-molecule organic solar cells

Three small-molecule donors based on dithieno [2,3-d:2’,3 ’-d’]-benzo[1,2-b:4,5-b’] dithiophene(DTBDT)unit were designed and synthesized by side chain regulation with chlorinated or/and sulfurated substitutions(namely ZR1,ZR1-Cl,and ZR1-S-Cl respectively),along with a crystalline non-fullerene acceptor IDIC-4 Cl with a chlorinated 1,1-dicyanomethylene-3-indanone(IC) end group.Energy levels,molar extinction coefficients and crystallinities of three donor molecules can be effectively altered by combining chlorination and sulfuration strategies.Especially,the ZR1-S-Cl exhibited the best absorption ability,lowest higher occupied molecular orbital(HOMO) energy level and highest crystallinity among three donors,resulting in the corresponding all-small-molecule organic solar cells to produce a high power conversion efficiency(PCE) of 12.05% with IDIC-4 Cl as an acceptor.     

A chlorinated non-fullerene acceptor for efficient polymer solar cells

Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future. Here, the strategy that uses chemical structure modification to optimize the photoelectric properties is reported. A new narrow bandgap (1.30 eV) chlorinated non-fullerene electron acceptor (Y15), based on benzo[d][1,2,3] triazole with two 3-undecyl-thieno[2′,3′:4,5] thieno[3,2-b] pyrrole fused -7-heterocyclic ring, with absorption edge extending to the near-infrared (NIR) region, namely A-DA'D-A type structure, is designed and synthesized. Its electrochemical and optoelectronic properties are systematically investigated. Benefitting from its NIR light harvesting, the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency (PCE) of 14.13%, when blending with a wide bandgap polymer donor PM6. Our results show that the A-DA'D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells (PSCs).     

Small bandgap non-fullerene acceptor enables efficient PTB7-Th solar cell with near 0 eV HOMO offset

Three small bandgap non-fullerene(SBG NFAs) acceptors,BDTI,BDTI-2 F and BDTI-4 F,based on a carbon-oxygen bridged central core and thieno[3,4-b]thiophene linker,end-capped with varied electronwithdrawing terminal groups,were designed and synthesized.The acceptors exhibit strong absorption from 600 nm to 1000 nm.The optimal device incorporating designed NFA and PTB7-Th polymer donor achieves a power conversion efficiency of 9.11% with near 0 eV HOMO offset.The work presents a case study of efficient non-fullerene solar cells with small HOMO offsets,which is achieved by blending PTB7-Th with fine-tuned SBG acceptor.     

Effects of various donor: acceptor blend ratios on photophysical properties in non-fullerene organic bulk heterojunctions

In this work, the donor:acceptor ratio effected photophysical properties of non-fullerene organic solar cells are comparatively investigated. Effective transportation of the photo-generated charge carriers can be obtained with the PDBD-T:ITIC ratio variation. There is no significant energy loss variation exists in the process of changing the D:A ratio.     

All-polymer solar cells utilizing low band gap polymers as donor and acceptor

All-polymer solar cells based on blends of the low band gap polymers poly{[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]} (PTB7) and poly{[N,N-9-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-bithiophene)} (P(NDI2OD-T2)) are demonstrated. The use of the donor polymer PTB7 instead of poly(3-hexylthiophene) results in a higher open-circuit voltage and an overall spectral response better matched to the solar spectrum. A power conversion efficiency of 1.1% is reported with a peak external quantum efficiency of 18% at a wavelength of 680 nm. The microstructure of PTB7:P(NDI2OD-T2) blends is also investigated using a combination of grazing-incidence wide-angle X-ray scattering (GIWAXS), near-edge X-ray fine-structure (NEXAFS) spectroscopy, atomic force microscopy (AFM), and scanning transmission X-ray microscopy (STXM). GIWAXS measurements show that PTB7:P(NDI2OD-T2) blends contain P(NDI2OD-T2) crystallites with a (100) thickness of 9.5 nm dispersed in an amorphous PTB7 matrix. STXM measurements indicate a lack of mesoscale phase separation, with AFM and NEXAFS measurements revealing a P(NDI2OD-T2)-rich top surface with fibrillar morphology. These results indicate that the pairing of low band gap polymers as both donor and acceptor polymers in all-polymer solar cells may be an effective strategy for realizing high-efficiency all-polymer solar cells. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013