基于自组装修饰银纳米线透明电极的柔性有机太阳能电池

银纳米线(AgNWs)透明电极具有出色的挠曲性和高电导率,是一类非常有潜力的柔性透明电极材料.然而AgNWs透明电极还存在表面粗糙度大、与衬底的附着力差、表面功函数与活性层能级不匹配等问题.针对上述问题,采用刮涂方法将AgNWs嵌入聚酰亚胺薄膜中,获得表面平整的AgNWs柔性透明电极,并通过Ag与巯基基团相互作用将五氟苯硫酚自组装到AgNWs电极表面,使AgNWs电极表面功函数从未处理的-4.88 eV提高到-5.06 eV,从而使其与活性层能级更加匹配.利用该电极作为柔性透明电极,在不采用任何阳极界面层的情况下制备的柔性有机太阳能电池最佳能量转换效率达到11.77%.本工作为AgNWs柔性电极的制备及功函数调控提供了新的研究思路,并为发展基于AgNWs柔性电极的高效柔性有机太阳能电池提供了一种简单有效的解决方案.     

聚合物太阳能电池活性层的形貌调控

聚合物太阳能电池由于制备工艺简单、重量轻、成本低廉、可制备大面积柔性器件等优点,成为新能源和材料科学中的重要研究方向.经过近10年的发展,聚合物太阳能电池的能量转换效率从2005年的5%提高到目前的10%左右,然而聚合物太阳能电池的活性层形貌仍是制约其能量转换效率的一个重要方面.本文围绕聚合物太阳能电池结构与性能的关系,重点介绍了活性层材料的分子设计(共轭主链调制、烷基侧链优化等)和加工方法(热退火、添加剂、三元溶剂、绿色溶剂等)对其微观形貌的影响,并展望了聚合物太阳能电池未来的发展趋势以及面临的关键挑战.     

透明电极中银纳米线制备方法的研究

由于质脆及成本昂贵等缺点,传统的透明导电材料铟锡氧化物(ITO)已不能满足柔性电子设备的需求。银纳米线具有高导电率、良好柔软性以及高透明度,被公认为是最具前景的ITO替代材料。它可以广泛应用于柔性透明电子设备,如可拉伸太阳能电池、可折叠智能手机以及有机发光二极管的透明导电薄膜(TCF)材料。以提高TCF透明度、降低薄层电阻为目标,本文从控制纳米银线的长径比、纳米线之间的接触电阻以及网络结构等几个方面,归纳总结了性能优良、工艺简单、可大规模制备Ag NWs的方法。     

基于银纳米线导电网络的电子纺织品

随着现代电子产品向微型化、集成化和柔性化的方向发展,以及人们对功能性、智能化和可穿戴纺织品需求的不断提高,电子纺织品(E-textiles)成为研究热点。银纳米线(AgNWs)具有高比表面积、导热、导电、透光、延展性、机械强度和柔性等优异性能,将AgNWs与纺织品结合具有制备步骤简单、易于集成、基本不影响织物的穿着舒适性、耐用性好、成本低、获得抗菌和防紫外功能等优势,是制备E-textiles的理想方法之一。本文首先介绍了共混法和后整理法这两种AgNWs导电纺织品的制备方法,然后介绍了近年来AgNWs在保暖纺织品、电热纺织品、柔性电子传感器、超弹性导电复合纤维、自供能纺织品等领域的研究进展。最后指出AgNWs在E-textiles领域存在的不足和未来的研究方向,以期为E-textiles的研究提供参考和借鉴。     

基于苝酸酯受体光伏器件的性能表征

近十几年来,基于有机聚合物半导体材料的太阳能电池,由于具有价格低廉,易于加工,不受材料种类限制和易于制备大面积柔性器件等优点,而受到极大关注．自从1992年发现从共轭聚合物的基态到富勒烯存在光诱导电子转移现象以来,有机聚合物太阳能电池的研究取得了较大进展,研究较多的是共轭聚合物为给体(D),富勒烯为受体(A)的体系,能量转换效率可达3．3％,苝酸酯是一类液晶材料,其结构高度有序且含有4个吸电子的酰基,使得它们适合电子传输,且在普通有机溶剂中具有良好的溶解性,与共轭聚合物有较好的相容性,因此可制成薄膜,本文的研究表明,苝酸酯也是一类良好的电子受体,与共轭聚合物给体匹配,可用于制备光伏器件——太阳能电池。     

电沉积法制备固态染料敏化太阳能电池

本文采用一步电化学沉积的方法在导电玻璃上先后沉积了ZnO/染料复合薄膜以及CuSCN薄层,实现仅以电沉积法制备结构为ZnO/染料/CuSCN的固态染料敏化太阳能电池,电池的光电转换效率达到0.1%.在电沉积CuSCN前,脱附电沉积制备的ZnO/染料复合薄膜中的染料以形成多孔ZnO薄膜,然后通过染料再吸附得到染料敏化ZnO纳晶多孔薄膜.在电沉积过程中,ZnO和CuSCN的晶体尺寸、晶体取向和膜层形貌都可以进行比较精准的控制.探讨了影响沉积薄膜形貌和光电转换效率的因素,如旋转圆盘电极的旋转速度、电沉积温度以及染料敏化剂的选择.本文报道的低温电沉积制备全固态太阳能电池的方法为制备柔性染料敏化太阳能电池提供了一种新的思路.     

基于苯并二噻吩的D-A型窄带隙共轭聚合物在太阳能电池中的应用

近年来为获得有机聚合物太阳能电池更高的能量转换效率,越来越多的活性层材料被设计合成出来,尤其是给体材料。其中,基于给体单元苯并二噻吩(BDT)的D-A型窄带隙共轭聚合物更是多次刷新了有机聚合物太阳能电池效率的最高记录,目前达10.6%。本文探讨了基于苯并二噻吩的D-A型窄带隙共轭聚合物材料结构及其应用在太阳能电池中的性能参数关系,从提高开路电压、短路电流和填充因子三个方面总结出了提高基于BDT共轭聚合物太阳能电池能量转换效率的方法。     

聚合物太阳能电池高效共轭聚合物给体和富勒烯受体光伏材料

聚合物太阳能电池（PSC）由共轭聚合物给体和富勒烯衍生物受体的共混膜（活性层）夹在ITO透明导电玻璃正极和低功函数金属负极之间所组成,具有制备过程简单、成本低、重量轻、可制备成柔性器件等突出优点,近年来成为国内外研究前沿和热点。当前研究的焦点是提高器件的光电能量转换效率,而提高效率的关键是高效共轭聚合物给体和富勒烯衍生...     

单晶二氧化钛纳米线的制备及其在柔性染料敏化太阳能电池中的应用

采用强碱水热法制备单晶二氧化钛纳米线(SCTNW),在高压高温和强碱作用下,二氧化钛颗粒的(010)晶面被NaOH溶液侵蚀,生成钛酸钠(Na2Ti4O9);经过酸洗后,生成钛酸水合物(H2Ti4O9·H2O),钛酸水合物之间通过氢键连接成线状;烧结失水后,最终形成SCTNW.通过透射电子显微镜(TEM)、选区电子衍射(SAED)、X射线能量散射谱(EDS)和X射线衍射(XRD)等手段进行表征和测试,分析了SCTNW的形成过程,探讨了水热时间对SCTNW形成的影响;将获得的SCTNW共混在二氧化钛纳米颗粒的胶体中,采用刮涂法在柔性钛箔上制备了染料敏化太阳能电池(DSSC)光阳极,通过扫描电子显微镜(SEM)、交流阻抗谱(EIS)、紫外-可见(UV-Vis)分光光度计和电池光电性能等表征和测试,探讨了SCTNW的共混量对柔性DSSC光电性能的影响.实验结果表明:当共混7.5%(w)的SCTNW时,所制备的柔性DSSC在100mW·cm-2模拟太阳光照下,光电转换效率达到6.48%.     

通过调节共轭聚合物侧链实现可绿色溶剂加工的非富勒烯太阳能电池

有机太阳能电池(OSC)经过长期的发展,其能量转换效率(PCE)已快速推进至14%–16%,基本接近可商业化应用的范围,但在目前所见报道的高效率OSC器件的制备过程中,活性层薄膜的加工大多采用氯苯、二氯苯、氯仿等毒性较高的含卤/芳香性试剂,此类试剂对环境及人类健康的危害非常高。在本工作中,我们基于已报道的高效率给体共轭聚合物PBDB-T,通过扩大共轭侧链结构与增长柔性烷基侧链的方式,合成了新型给体聚合物PBDB-DT。PBDB-DT中较长的柔性烷基侧链保证了其在低毒性溶剂四氢呋喃(THF)溶液中良好的溶解度,同时,扩大的共轭侧链也有效增强了其在THF中的溶液聚集作用,这一特性对于在非富勒烯型OSC器件中获得较好的光伏性能尤其重要。当采用非富勒烯小分子IT-M作为电子受体材料时,以THF为主溶剂加工的基于PBDB-DT:IT-M的OSC器件可以获得10.2%的能量转换效率。     

Flexible ITO-free organic solar cells over 10% by employing drop-coated conductive PEDOT:PSS transparent anodes

Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonic acid)(PEDOT:PSS) has been explored to fabricate flexible and stretchable conductors. Generally, PEDOT:PSS transparent anodes are prepared by spin-coating method. In this article, we adopt a method by dropping PEDOT:PSS aqueous solution on the PET plastic substrate to fabricate flexible electrodes. Compared with spin coating, drop-coating is simple and cost-effective with large-area fabrications. Through this method, we fabricated highly transparent conductive electrodes and systematically studied their electrical, optical, morphological and mechanical properties. With dimethyl sulfoxide/methanesulfonic acid(DMSO/MSA) treated PEDOT:PSS electrode,bendable devices based on non-fullerene system displayed an open-circuit voltage of 0.925 V, a fill factor of 70.74%, and a high power conversion efficiency(PCE) of 10.23% under 100 mW cm~(-2) illumination, which retained over 80% of the initial PCE value after 1000 bending cycles. Based on the findings, drop-coated PEDOT:PSS electrodes exhibited high suitability for the development of large-area and high-efficiency printed solar cell modules in the future.     

基于量子点涂料的柔性光阳极及碳基对电极的制备和优化

首先制备出量子点(QDs)/TiO_2涂料,分别采用丝网印刷法与刀刮法将涂料涂覆于ITO/PET柔性基底上,结果表明刀刮法制备量子点敏化太阳电池(QDSCs)效果更佳,且具有普适性。基于铜片对电极所组装的ZnCuInSe,CdSe和CdSeTe量子点半柔性QDSCs最高效率分别达2.83%,2.46%和1.99%。另外,我们对石墨纸进行表面化学修饰以提高亲水性,再通过简单的连续离子交换吸附法(SILAR)在石墨纸上负载Cu_xS纳米粒子,制备出Cu_xS/GP柔性对电极,进一步组装成全柔性QDSCs,获得了2.13%光电转化效率。     

基于量子点涂料的柔性光阳极及碳基对电极的制备和优化

首先制备出量子点（QDs）/TiO₂涂料,分别采用丝网印刷法与刀刮法将涂料涂覆于ITO/PET柔性基底上,结果表明刀刮法制备量子点敏化太阳电池（QDSCs）效果更佳,且具有普适性。基于铜片对电极所组装的ZnCuInSe,CdSe和CdSeTe量子点半柔性QDSCs最高效率分别达2.83%,2.46%和1.99%。另外,我们对石墨纸进行表面化学修饰以提高亲水性,再通过简单的连续离子交换吸附法（SILAR）在石墨纸上负载Cu_xS纳米粒子,制备出Cu_xS/GP柔性对电极,进一步组装成全柔性QDSCs,获得了2.13%光电转化效率。     

A universal tactic of using Lewis-base polymer-CNTs composites as additives for high performance cm~2-sized and flexible perovskite solar cells

Lewis-base polymers have been widely utilized as additives to act as a template for the perovskite nucleation/crystal growth and passivate the under-coordinated Pb2+ sites.However,it is uncovered in this work that the polymer on the perovskite grain boundaries would significantly hinder the charge transport due to its low conductivity,which brings about free carrier recombination and photocurrent losses.To circumvent this issue while fully exploiting the benefits of polymers in passivating the trap states in perovskite,we incorporate highly conductive multiwall carbon nanotubes(CNTs) with Lewis-base polymers as coadditives in the perovskite film.Functionalizing the CNTs with-COOH group enables a selective hole-extraction and charge transport from perovskite to the hole transporting materials(HTM).By studying the charge transporting and recombination dynamics,we revealed the individual role of the polymer and CNTs in passivating the trap states and facilitating the charge transport,respectively.As a result,the perovskite solar cells(PSCs) with polymer-CNTs composites exhibit an impressive PCE of 21.7% for a small-area device(0.16 cm2) and 20.7% for a large-area device(1.0 cm2).Moreover,due to the superior mechanical flexibility of both polymer and CNTs,the polymer-CNTs composites incorporation in the perovskite film encourages the fabrication of flexible PSCs(f-PSCs) with an impressive PCE of 18.3%,and a strong mechanical durability by retaining 80%of the initial PCE after 1,000 times bending.In addition,we proved that the selection criteria of the polymers can be extended to other long-chain Lewis-base polymers,which opens new possibilities in design and synthesis of inexpensive material for this tactic towards the fabrication of high performance large-area PSCs and f-PSCs.     

n‐Type Conjugated Polymer Based on Dicyanodistyrylbenzene and Naphthalene Diimide Units for All‐Polymer Solar Cells

All polymer solar cells (all‐PSCs), possessing superior mechanical strength and flexibility, offer the commercialization opportunity of the PSCs for flexible and portable devices. In this work, we designed and synthesized two copolymer acceptors based on dicyanodistyrylbenzene (DCB) and naphthalene diimide (NDI) units. The corresponding copolymer acceptors are denoted as PDCB‐NDI812 and PDCB‐NDI1014. The medium band gap copolymer PBDB‐T was selected as donor material for investigation of the photovoltaic performance. Two all‐PSCs devices showed power conversion efficiencies (PCE) of 4.26% and 3.43% for PDCB‐NDI812 and PDCB‐NDI1014, respectively. The improved PCE was ascribed to the higher short‐circuit current (J_SC), greater charge carrier mobility and higher exciton dissociation probability of the PBDB‐T:PDCB‐NDI812 blend film. These results suggest that DCB unit and NDI unit based copolymer acceptors are promising candidates for high performance all‐PSCs.     

Constructing a Strongly Absorbing Low‐Bandgap Polymer Acceptor for High‐Performance All‐Polymer Solar Cells

All‐polymer solar cells (all‐PSCs) offer unique morphology stability for the application as flexible devices, but the lack of high‐performance polymer acceptors limits their power conversion efficiency (PCE) to a value lower than those of the PSCs based on fullerene derivative or organic small molecule acceptors. We herein demonstrate a strategy to synthesize a high‐performance polymer acceptor PZ1 by embedding an acceptor–donor–acceptor building block into the polymer main chain. PZ1 possesses broad absorption with a low band gap of 1.55 eV and high absorption coefficient (1.3×10⁵ cm⁻¹). The all‐PSCs with the wide‐band‐gap polymer PBDB‐T as donor and PZ1 as acceptor showed a record‐high PCE of 9.19 % for the all‐PSCs. The success of our polymerization strategy can provide a new way to develop efficient polymer acceptors for all‐PSCs.     

Flexible transparent PES/silver nanowires/PET sandwich-structured film for high-efficiency electromagnetic interference shielding

We have developed a kind of high-yield synthesis strategy for silver nanowires by a two-step injection polyol method. Silver nanowires and polyethylene oxide (PEO) (M(w) = 900,000) were prepared in a homogeneous-coating ink. Wet composite films with different thicknesses were fabricated on a PET substrate by drawn-down rod-coating technology. Silver nanowires on PET substrates present a homogeneous distribution under the assistance of PEO. Then PEO was thermally removed in situ at a relatively low temperature attributed to its special thermal behavior under atmospheric conditions. As-prepared metallic nanowire films on PET substrates show excellent stability and a good combination of conductivity and light transmission. A layer of transparent poly(ethersulfones) (PESs) was further coated on silver nanowire networks by the same coating method to prevent the shedding and corrosion of silver nanowires. Sandwich-structured flexible transparent films were obtained and displayed excellent electromagnetic interference (EMI) shielding effectiveness.     

Mixed-phase Mesoporous TiO2 Film for High Efficiency Perovskite Solar Cells

Mesoporous scaffold structures have played great roles in halide perovskite solar cells(PSCs),due to the excellent photovoltaic performance and commercial perspective of mesoporous PSCs.Here,we reported a mixed-phase TiO2 mesoporous film as an efficient electron transport layer(ETL)for mesoporous perovskite solar cells.Due to the improved crystal phase,fihn thickness and nanopartMe size of TiO2 layer,which were controlled by varying the one-step hydrothermal reaction time and annealing time,the PSCs exhibited an outstanding short circuit photocurrent density of 25.27 mA/cm^2,and a maximum power conversion efficiency(PCE)of 19.87%.It is found that the ultra-high Jsc attributes to the excellent film quality,light capturing and excellent electron transport ability of mixed-phase TiO2 mesoporous film.The results indicate that mix-phase mesoporous metal oxide fihns could be a promising candidate for producing effective ETLs and high efficiency PSCs.     

Conductivity enhancement of PEDOT:PSS film via sulfonic acid modification: application as transparent electrode for ITO-free polymer solar cells

3-Hydroxy-1-propanesulfonic acid(HPSA)was applied as a modification layer on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)film via spin-coating,resulting in a massive boost of the conductivity of PEDOT:PSS film,and thus the as-formed PEDOT:PSS/HPSA bilayer film was successfully used as a transparent electrode for ITO-free polymer solar cells(PSCs).Under the optimized concentration of HPSA(0.2 mol L~(-1)),the PEDOT:PSS/HPSA bilayer film has a conductivity of 1020 S cm~(-1),which is improved by about 1400 times of the pristine PEDOT:PSS film(0.7 S cm~(-1)).The sheet resistance of the PEDOT:PSS/HPSA bilayer film was 98Ωsq~(-1),and its transparency in the visible range was over 80%.Both parameters are comparable to those of ITO,enabling its suitability as the transparent electrode.According to atomic force microscopy(AFM),UV-Vis and Raman spectroscopic measurements,the conductivity enhancement was resulted from the removal of PSS moiety by methanol solvent and HPSA-induced segregation of insulating PSS chains along with the conformation transition of the conductive PEDOT chains within PEDOT:PSS.Upon applying PEDOT:PSS/HPSA bilayer film as the transparent electrode substituting ITO,the ITO-free polymer solar cells(PSCs)based on poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]:[6,6]-phenyl C71-butyric acid methyl ester(PC_(71)BM)(PCDTBT:PC_(71)BM)active layer exhibited a power conversion efficiency(PCE)of 5.52%,which is comparable to that of the traditional ITO-based devices.     

Time-resolved electrochromic properties of MoO<Subscript>3</Subscript> thin films electrodeposited on a flexible substrate

In this paper, a MoO₃ thin film was firstly electrodeposited on flexible ITO/PET substrates. Its electrochromic properties were examined using an electrochemical workstation coupled in situ with a charge-coupled device (CCD) spectrophotometer. The film was characterized by XRD and AFM. The electrodeposited MoO₃ thin film on the ITO/PET substrate showed a large transmittance contrast between the colored and bleached states, a quick response, and good durability and reversibility. The low working potential range, –0.5 to 1.6 V (vs. Ag/AgCl), for the MoO₃/ITO/PET film prepared in this work makes it a good candidate for flexible smart windows, as well as other plastic electrochromic devices. Electronic Publication