基于无规三元共聚物的非卤溶液加工型高效聚合物太阳能电池（英文）

在本工作中,我们以烷硫基噻吩基取代的苯并二噻吩(BDTT-S)为给体单元、5,6-二氟取代苯并三唑(FBTz)和噻唑并噻唑(TTz)为弱吸收电子受体单元,设计合成了一系列宽带隙的无规三元共聚物给体材料。通过改变两个受体单元FBTz和TTz在聚合物中的摩尔比,有效调节了聚合物的光学、电化学、分子排列以及电荷传输性能。最终,使用非卤溶剂为加工溶剂,以三元共聚物PSBTZ-60为给体、ITIC为非富勒烯受体的聚合物太阳能电池(PSCs)获得了10.3%的能量转换效率(PCE),其中开路电压为0.91 V,短路电流为18.0 mA·cm-2,填充因子为62.7%;与之相比,在相同的器件制备条件下,基于PSTZ:ITIC的PSCs仅获得8.5%的PCE,基于PSBZ:ITIC的PSCs也仅获得8.1%的PCE。这些结果表明:三元无规共聚能够作为一种简单且实用的策略去设计、合成高性能聚合物光伏材料。     

基于噻吩并吡嗪类的-(D-A_1)_m-(D-A_2)_n-型三元无规共聚物的合成及光电性能

选用苯并二噻吩(BDT)类衍生物作为给体单元D,并选用噻吩并吡咯二酮(TPD)类衍生物(A1)和噻吩并吡嗪(TP)类衍生物(A2)作为共同的受体单元,通过Stille偶联聚合制备了-(DA_1)_m-(D-A_2)_n-型三元无规共聚物,并同时合成了基于BDT和TP的二元共聚物。采用核磁共振氢谱(1 H-NMR)、凝胶液相色谱(GPC)和热重(TG)表征聚合物的结构与性能;采用紫外-可见光谱和循环伏安法测试聚合物的光电性能,研究了以这类聚合物为给体材料制备的太阳能器件的光伏性能。结果表明:三元无规共聚物具有较高的相对分子量和热稳定性,在太阳光范围具有强而宽的吸收,同时具有相对较低的最高电子占用轨道HOMO和最低电子占用轨道LUMO能级。基于三元无规共聚物P2的器件,其光电转换效率可达到1.22%,优于相应的二元共聚物P1的1.15%。     

非富勒烯聚合物太阳电池研究进展

综述了以p-型共轭聚合物为给体、n-型有机半导体为受体的非富勒烯聚合物太阳电池光伏材料最新研究进展,包括n-型共轭聚合物和可溶液加工小分子n-型有机半导体(n-OS)受体光伏材料,以及与之匹配的p-型共轭聚合物给体光伏材料.介绍的n-型共轭聚合物受体光伏材料包括基于苝酰亚胺(BDI)、萘酰亚胺(NDI)以及新型硼氮键连受体单元的D-A共聚物受体光伏材料,目前基于聚合物给体(J51)和聚合物受体(N2200)的全聚合物太阳电池的能量转换效率最高达到8.26%.n-OS小分子受体光伏材料包括基于BDI和NDI单元的有机分子、基于稠环中心给体单元的A-D-A型窄带隙有机小分子受体材料等.给体光伏材料包括基于齐聚噻吩和苯并二噻吩(BDT)给体单元的D-A共聚物,重点介绍与窄带隙A-D-A结构小分子受体吸收互补的、基于噻吩取代BDT单元的中间带隙二维共轭聚合物给体光伏材料.使用中间带隙的p-型共轭聚合物为给体、窄带隙A-D-A结构有机小分子为受体的非富勒烯聚合物太阳电池能量转换效率已经突破12%,展示了光明的前景.最后对非富勒烯聚合物太阳电池将来的发展进行了展望.     

基于1,2,4-三氮唑衍生物的共轭聚合物的合成及其光伏性能

以缺电子的1,2,4-三氮唑衍生物作为拉电子结构单元(A), 以富电子的噻吩或苯并二噻吩衍生物作为推电子结构单元(D), 通过Stille偶联聚合的方法, 合成了三种主链型D-A(推-拉电子结构)的交替共聚物PT-TZ, PB-TZ和PB-TTZT. 不同富电子结构单元可使其聚合物表现出不同的光物理性能和光伏性能. 嵌入较多的噻吩单元, 可有效增大聚合物主链的共轭长度, 拓宽其吸收光谱, 因此, 聚合物PB-TTZT的光伏性能明显优于另外两种聚合物. 以三种聚合物分别作为给体材料, 以PC₆₁BM作为受体材料, 制备了聚合物太阳能电池(PSCs), 其中, 基于PB-TTZT的PSCs器件在AM 1.5 G模拟太阳光条件下的光电转换效率为1.18%.     

基于侧链为烷基硫苯的萘二酰亚胺单元的新型聚合物受体的合成及其光电性能

以N-（4-巯基苯基）乙酰胺、7-（溴甲基）十五烷和二溴萘二羧酸酐为原料合成了侧链为烷基硫苯的萘二酰亚胺（NDI）衍生物,将其作为受体单元,硒吩衍生物为给体单元,合成了基于NDI的新型聚合物受体(PNDI PSHD),同时合成了基于苯并二噻吩的D-A型共聚物PBDT(T) TPD作为给体材料,将聚合物给体、受体混合制备聚合物太阳能器件。聚合物的结构和光电性能经¹H NMR、 GPC、 UV、 CV和荧光发射光谱表征,并测试了器件的光伏性能。结果表明：给受体聚合物均具有较高的相对分子量,在太阳光范围具有强而宽的吸收,同时具有相对较低的最高电子占用轨道（HOMO）和最低电子未占用轨道（LUMO）能级,给受体聚合物混合后引起荧光猝灭,器件的能量转换效率（PCE）达到0.72%。     

高性能聚合物光伏材料的设计与应用

高性能聚合物光伏材料对于推动聚合物太阳能电池领域的发展具有十分重要的作用.随着研究的深入,聚合物光伏材料从早期的聚噻吩体系逐步发展到具有推拉电子作用的给体-受体(D-A)交替共聚物,其相应的器件光伏效率也从最初的1%左右提升到如今超过11%.近十年来,种类繁多的给受体单元被开发并应用于聚合物材料的构建中,其中基于苯并二噻吩(BDT)单元的聚合物材料因为具有良好的光伏性能,得到了十分广泛的应用.近年来,非富勒烯受体的迅速发展给聚合物太阳能电池的研究注入了新的活力,BDT类聚合物在基于非富勒烯受体的聚合物太阳能电池中也展现出重要的作用,已经获得了超过11%的光电转化效率.本文简要介绍了我们在高性能聚合物光伏材料的设计与应用中的相关工作,主要分为聚噻吩和苯并二噻吩材料的设计与应用、活性层形貌调控以及非富勒烯聚合物太阳能电池的相关研究.     

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（英文）

在各种共轭聚合物给体材料中,以聚3-己基噻吩为代表的聚噻吩衍生物因其结构简单、易制备以及良好的空穴传输性能,在富勒烯衍生物为受体材料的聚合物太阳能电池体系中一直是研究重点之一。但是在近年来发展迅速的稠环小分子非富勒烯体系中的相关研究较少。在本工作中,我们通过在噻吩侧链引入烷硫基和氟取代基,设计合成了一种新型的聚噻吩衍生物给体PBSBT-2F;并对其吸收光谱、分子能级、传输性能以及光伏性能进行研究。基于PBSBT-2F:ITIC的聚合物太阳能电池取得6.7%的能量转换效率,其中开路电压为0.75 V,短路电流为13.5 mA·cm~(-2),填充因子为66.6%。结果表明:PBSBT-2F在非富勒烯体系中有很大的应用潜力。     

基于3,4-二氰基噻吩的宽带隙共轭聚合物的设计合成与光伏应用

利用3,4-二氰基噻吩(DCT)为电子受体单元,苯并双噻吩(BDT)为电子给体单元,并结合不同侧链取代的噻吩为π桥,设计合成了一系列新型宽带隙共轭聚合物:PB3TCN-C32、PB3TCN-C36、PB3TCN-C36-R以及PB3TCN-C40.这些聚合物具有较宽的光学带隙( 1.8 eV)、较深的最高占有分子轨道(HOMO)能级.与非富勒烯受体(IT-4F)结合制备了有机太阳电池器件,其中聚合物PB3TCN-C40实现了高达11.2%的能量转换效率(PCE),其开路电压(V_(oc))为0.92 V,短路电流密度(J_(sc))为18.9 mA cm~(-2),填充因子(FF)为0.64,是目前文献报道基于氰基噻吩类聚合物材料的最好结果.同时,该体系具有低至0.6 eV的能量损失.这些结果表明DCT是一种极具潜力的实现宽带隙、深HOMO能级共轭聚合物的构筑单元,有望实现更高能量转换效率的有机太阳电池.     

主链含噻唑单元的新型聚噻吩衍生物的合成与光伏性能

聚噻吩(PT)衍生物由于简单易合成和较好的光电性能,被广泛运用于有机太阳能电池(OSCs)中,但PT较高的能级限制了其在非富勒烯类OSCs的应用。为了降低PT的能级结构,本研究将噻唑单元引入到聚噻吩主链中,设计并合成了新型聚合物给体材料PBTzCl-T。通过紫外-可见吸收光谱、电化学循环伏安法及密度泛函理论(DFT)计算等对聚合物的结构、光学和电学性能进行了表征,并对制备的光伏器件进行了光电性质研究。结果表明：噻唑的引入能够有效降低聚合物的HOMO和LUMO能级,从而提高光伏器件的开路电压。PBTzCl-T在不同溶剂中表现出不同的预聚集行为,进而影响聚合物给受体界面处的电荷转移能力和活性层形貌,导致光伏器件的短路电流和填充因子变化。     

以噻吩[3,4-b]并噻吩为核的近红外电子受体及其高性能光探测器

为了实现在近红外区的良好光电响应,设计合成了一种A-D-A型有机电子受体TCIC.由于采用具有强醌式效应的噻吩[3,4-b]并噻吩单元为核,TCIC在780～1000 nm的近红外区具有强吸收以及合适的能级结构,可与常用的聚合物给体PCE10的吸收和能级相匹配.于是,采用2种器件结构,制备了基于PCE10×TCIC共混...     

以绕丹宁和噻唑烷-2,4-二酮为端基的不对称结构有机受体分子的设计合成与构性关系探讨

分别以绕丹宁和噻唑烷-2,4-二酮单元为端基、IDT为中心核设计合成了一个新型不对称结构的有机小分子受体IDT-2,并通过与两端均以绕丹宁或噻唑烷-2,4-二酮受体单元的对称小分子受体IDT-1和IDT-3进行对比,探讨了分子结构与性能之间的关系。研究发现,从IDT-1到IDT-3,随着两端的绕丹宁基团被噻唑烷-2,4-二酮基团逐步取代,这类小分子受体的吸收光谱显著蓝移,光学带隙E_g~(opt)逐步增大,LUMO和HOMO能级也逐渐抬升。随后我们分别以这三个小分子为受体、P3HT为给体共混构建活性层而制备了有机太阳能电池,结果表明,以两端均为绕丹宁单元的对称结构小分子受体IDT-1构建的电池器件具有最高的光电转换效率(PCE),相应的J_(sc)和FF值也最大,而V_(oc)则最低;而以两端均为噻唑烷-2,4-二酮基团的对称结构小分子受体IDT-3的电池器件,其V_(oc)最高,但其J_(sc)和FF则最低,PCE值也最小。对于IDT-2而言,由于分子只有一个绕丹宁单元被噻唑烷-2,4-二酮所取代,其V_(oc),J_(sc)和PCE均介于IDT-1与IDT-3之间。由此说明,尽管噻唑烷-2,4-二酮基团的引入能有效提升器件V_(oc),但却不利于改善其J_(sc)和FF,因此受体的分子设计中如何平衡电池器件的几种光伏性能参数而获得高的光电转换效率仍是十分重要的研究课题之一。     

苝二酰亚胺:有机膦盐基双组份共混电子传输层及其开路电压接近1.0 V的非富勒烯聚合物太阳电池

The fabrication of high-efficiency organic solar cells requires a cathode interlayer (CIF) having multiple properties such as forming an ohmic contact with the active layer, high electron conductivity, low-density traps, and hole blocking. These roles can be more completely fulfilled by using a suitable binary blended CIF rather than a single molecule based CIF. In this article, we present the roles by using binary blended PDINO (amino N-oxide perylene diimide) and QPhPBr (tetraphenylphosphonium bromide) as the CIF to fabricate fullerene-free polymer solar cells (PSCs) with PBDB-T:IDTBR, a new donor: acceptor combination, as the active layer. The high-lying lowest unoccupied molecular orbital of the acceptor and the low-lying highest occupied molecular orbital (HOMO) of the polymer with small driving force (the donor-acceptor HOMO-HOMO energy offset, ∆HOMO) for the hole transfer, both result in a high open circuit voltage (V_oc). Moreover, our strategy to insert a dual mixed solution of CIF over the blended active layer better facilitates the role, which significantly improves charge extraction and collection, leading to the high V_oc, short-circuit current density (J_sc), and fill factor (FF) observed in comparison to a single CIF material. It was observed that the power conversion efficiency (PCE) increases to 8.27%, with a high V_oc of 1.0 V, using a binary mixture of CBL. Such tremendous improvements in V_oc using well known polymer donors have not been reported till date in binary solar cell systems. This idea demonstrates that the minimum energy loss because of the small ∆HOMO of the D-A combination and the use of a dual mixed layer of CBL together present the future prospects of non-fullerene photovoltaic devices for researchers.     

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.     

Influence of pyrimidine additives in electrolytic solution on dye-sensitized solar cell performance

The influence of pyrimidine additives on the performance of a bis(tetrabutylammonium)cis-bis(thiocyanato)bis(2,2′-bipyridine-4-carboxylic acid, 4′-carboxylate)ruthenium(II) dye-sensitized TiO₂ solar cell with an I⁻/I₃⁻ redox electrolyte in acetonitrile was studied. The current–voltage characteristics were measured for more than 10 different pyrimidine derivatives under AM 1.5 (100 mW/cm²). The pyrimidine additives tested had varying effects on the performance of the cell. The additives drastically enhanced the open-circuit photovoltage (V_oc) and the solar energy conversion efficiency (η), but usually reduced the short circuit photocurrent density (J_sc) of the solar cell. Physical and chemical properties of the pyrimidines were computationally calculated in order to determine the reasons for the additive effects on cell performance. Consequently, the greater the calculated partial charge of the nitrogen atoms in the pyrimidine groups, the larger the V_oc but the smaller the J_sc values. The V_oc of the cell also increased as the ionization energy of the pyrimidine molecules decreased. Moreover, as the calculated dipole moment of the pyrimidine derivatives increased, the J_sc value was reduced, but the V_oc value was enhanced. These results suggest that the electron donicity of pyrimidine additives influenced the interaction with TiO₂ electrode and I⁻/I₃⁻ electrolyte, which lead to the changes in dye-sensitized solar cell performance.     

染料敏化纳米薄膜太阳电池中DMPII浓度的优化

利用超微铂电极和循环伏安法及电化学阻抗谱研究了在1,2-二甲基-3-丙基咪唑碘(DMPII)的3-甲氧基丙腈(MePN)溶液中I₃^－和I^－的氧化还原行为，并对比了由不同浓度的I2和DMPII组成的电解质溶液，其染料敏化纳米薄膜太阳电池(DSCs)的光伏性能. 发现以MePN为溶剂，含1.0 mol•dm^-3 DMPII、0.12 mol•dm^-3 I2、0.10 mol•dm^-3 LiI和0.50 mol•dm^-3 4-叔丁基吡啶的电解质溶液，其DSCs的短路光电流密度为16.67 mA•cm^-3、开路电压为0.69 V、填充因子为0.70、光电转换效率达8.08%.     

两亲性季铵盐对钙钛矿太阳能电池效率和稳定性的影响

将廉价易得的两亲性季铵盐十六烷基三甲基溴化铵（CTMAB）加入到钙钛矿前驱体溶液中，通过调节添加量研究了CTMAB对钙钛矿太阳能电池效率和稳定性的影响.结果表明，加入CTMAB后制备的钙钛矿薄膜更加致密均匀，表面缺陷更少，钙钛矿晶体结晶性得到显著提高，从而提高了电池的光电转换效率及电池稳定性；含有CTMAB的钙钛矿太阳能电池的光电转换效率（PCE）为18.03%，明显高于未添加CTMAB的电池效率（17.05%）；含有CTMAB的电池稳定性有较大的提高，在一定湿度环境中保存40 d后效率仍达初始效率的95%，而未添加CTMAB的器件效率只有初始效率的70%.     

Ternary solvent-processed efficient organic solar cells based on a new A-DA'D-A acceptor derivative employing the 3rd-position branching side chains on pyrroles

Recent advances in non-fullerene acceptors(NFAs),typically Y6,have driven power conversion efficiency(PCE) of single-junction orga nic solar cells(OSCs) over 16%.Mea nwhile,it becomes essential to know how to adopt simple strategies to further improve device performance.In this work,a new A-DA'D-A acceptor derivative,Y19-N3 employing 3-ethylheptyl branched at the 3^rd-position instead of 2-ethylhexyl on the pyrroles of Y19 is reported.The selection of an appropriate solvent in casting device is implemented to maximize the photovoltaic performance.PBDB-T:Y19-N3-based OSCs treated with a ternary solvent of CF/CB(1:3,v/v) and 0.8% DIO exhibit the optimal PCE of 13.77% here,with the significantly improved V_oc(0.78 V) and FF(0.72) as well as the high J_sc(24.46 mA/cm²).Further characterizations indicate that this ternary solvent-treated PBDB-T/Y19-N3 film exhibits the more appropriate morphological features with the highly efficient charge generation and collection as well as the more balanced electron and hole mobilities.This work combines molecular design and device engineering to improve the photovoltaic properties,which is important to the development of OSCs.     

绝缘氧化物包覆对钙钛矿太阳电池性能及界面电荷复合动力学的影响

采用浸渍法对钙钛矿太阳电池的介孔层TiO₂纳米颗粒进行了SiO₂、ZrO₂、Al₂O₃几种绝缘氧化物包覆,研究了其对电池光伏性能以及界面电荷复合动力学的影响。结果表明, SiO₂包覆之后,电池的填充因子(FF)从67.6%提高到72.3%,光电转换效率提升到13.7%, ZrO₂和Al₂O₃包覆导致电池开路电压提升约50mV,但是短路电流(J_sc)和填充因子略有下降。采用纳秒时间尺度的瞬态吸收光谱技术,从时间分辨的角度分析了钙钛矿电池界面的电子和空穴的复合寿命,对电池性能的变化给出了合理的解释。     

骨架非稠合的电子受体在聚合物太阳能电池中的应用

Non-fullerene electron acceptors have attracted enormous attention of the research community owing to their advantages of optoelectronic and chemical tunabilities for promoting high-performance polymer solar cells (PSCs). Among them, fused-ring electron acceptors (FREAs) are the most popular ones with the good structural planarity and rigidity, which successfully boost the power conversion efficiencies (PCEs) of PSCs to over 14%. In considering the cost-control of future scale-up applications, it is also worthwhile to explore novel structures that are easy to synthesize and still maintain the advantages of FREAs. In this work, we design and synthesize a new electron acceptor with an unfused backbone, 5, 5'-((2, 5-bis((2-hexyldecyl)oxy)-1, 4-phenylene)bis(thiophene-2-yl))bis(methanylylidene)) bis(3-oxo-2, 3-dihydro-1H-indene-2, 1-diylidene))dimal-ononitrile (ICTP), which contains two thiophenes and one alkoxy benzene as the core and 2-(3-oxo-2, 3-dihydroinden-1-ylidene) malononitrile (IC) as the terminal groups. The synthetic route to ICTP involves only three steps, with high yields. Density functional theory calculations indicate that the non-covalent interactions, O…H and O…S, help reinforce the space conformation between the central core and the terminals. ICTP shows broad and strong absorption in the long-wavelength range between 500 and 760 nm. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of ICTP were measured to be -5.56 and -3.84 eV by cyclic voltammetry. The suitable absorption and energy levels make ICTP a good acceptor candidate for medium bandgap polymer donors. The best devices based on PBDB-T:ICTP showed a PCE of 4.43%, with an open circuit voltage (V_OC) of 0.97 V, a short circuit current density (J_SC) of 8.29 mA∙cm^-2, and a fill factor (FF) of 0.55, after adding 1% 1, 8-diiodooctane (DIO) as the solvent additive. Atomic force microscopy revealed that DIO could ameliorate the strong aggregation in the blended film and lead to a smoother film surface. The hole and electron mobilities of the optimized device were measured to be 9.64 and 2.03 × 10^-5 cm²∙V^-1∙s^-1, respectively, by the space-charge-limited current method. The relatively low mobilities might be responsible for the moderate PCE. Further studies can be performed to enlarge the conjugation length by including more aromatic rings. This study provides a simple strategy to design non-fullerene acceptors and a valuable reference for the future development of PSCs.     

基于苯甲酸受体的咔唑染料敏化剂的合成和光电性能

选择N-正丁基咔唑作为电子给体,芴酮作为桥键,苯甲酸作为受体,通过桥键芴酮与给体和受体连接位置的改变,设计合成了两个咔唑染料4-(6-(N-正丁基咔唑-3-基)-9-氧-9H-芴-3-基)苯甲酸(HXL-3W)和4-(7-(N-正丁基咔唑-3-基)-9-氧-9H-芴-2-基)苯甲酸(HXL-4Z).对咔唑染料的光谱性能、电化学性能和光电转换性能进行了研究,并运用密度泛函理论(DFT)方法对其几何结构和紫外-可见光谱进行了优化计算.结果表明, HXL-4Z的吸收光谱呈现两个明显的π→π^*跃迁吸收峰和一个较小的对应于分子内电荷转移的吸收峰,而HXL-3W的吸收光谱则仅呈现一个π→π^*跃迁吸收峰,且摩尔吸光系数远小于HXL-4Z.可能是HXL-3W分子结构中给体和受体距离较近,张力较大,导致较差的分子平面性和分子内电荷转移.因而HXL-4Z的光吸收能力和电子注入效率较优,从而具有较好的光电转换效率(2.03%) (短路电流(J_SC) = 3.88 mA·cm^-2,开路电压(V_OC) = 700 mV,填充因子(FF) = 0.75).