Vacuum relaxation and annealing-induced enhancement of mobility of regioregular poly(3-hexylthiophene) field-effect transistors

In order to enhance the performance of regioregular poly（3-hexylthiophene） （RR-P3HT） field-effect transistors （FETs）, RR-P3HT FETs are prepared by the spin-coating method followed by vacuum placement and annealing. This paper reports that the crystal structure, the molecule interconnection, the surface morphology, and the charge carrier mobility of RR-P3HT films are affected by vacuum relaxation and annealing. The results reveal that the field-effect mobility of RR-P3HT FETs can reach 4.17×10^-2m^2/（V·s） by vacuum relaxation at room temperature due to an enhanced local self-organization. Furthermore, it reports that an appropriate annealing temperature can facilitate the crystal structure, the orientation and the interconnection of polymer molecules. These results show that the field-effect mobility of device annealed at 150 ℃ for 10 minutes in vacuum at atmosphere and followed by placement for 20 hours in vacuum at room temperature is enhanced dramatically to 9.00×10^-2m^2/（V·s）.

Effects of concentration and annealing on the performance of regioregular poly(3-hexylthiophene) field-effect transistors

This paper investigates the effects of concentration on the crystalline structure, the morphology, and the charge carrier mobility of regioregular poly（3-hexylthiophene） （RR-P3HT） field-effect transistors （FETs）. The RR-P3HT FETs with RR-P3HT as an active layer with different concentrations of RR-P3HT solution from 0.5 wt% to 2 wt% are prepared. The results indicate that the performance of RR-P3HT FETs improves drastically with the increase of RR-P3HT weight percentages in chloroform solution due to the formation of more microcrystalline lamellae and bigger nanoscale islands. It finds that the field-effect mobility of RR-P3HT FET with 2 wt% can reach 5.78×10^-3 cm^2/Vs which is higher by a factor of 13 than that with 0.5 wt%. Further, an appropriate thermal annealing is adopted to improve the performance of RR-P3HT FETs. The field-effect mobility of RR-P3HT FETs increases drastically to 0.09 cm^2/Vs by thermal annealing at 150 ℃, and the value of on/off current ratio can reach 104.

Regioregular Asymmetric Diketopyrrolopyrrole Copolymers with Good Molecular Ordered Assembly Ability for High-performance Polymer Transistors

Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers,as asymmetric units can not only regulate solubility and energy levels,but also molecular stacking and orientation,thus giving much higher optoelectronic properties.However,very few studies have been reported in this field.The semiconducting properties of conjugated polymers could be regulated through regioregularity adjustment.Here,we took the asymmetric thiophene/pyridine side group DPP as core and developed the regioregular monomer T-Py-DPP through three steps:alkyl chain introduction,tin monomer coupling and NBS double bromination.The T-Py-DPP monomer was polymerized into reg-PPy TDPP-2FBT with a head-to-head structure.The regioregularity of T-Py-DPP unit endowed reg-PPy TDPP-2FBT with backbone planarity,self-assembly orientation,network-like morphology and high crystallinity in films,thus the superior bipolar transport properties.The highest hole and electron mobilities of reg-PPy TDPP-2FBT were 0.93 and 0.57 cm^(2)·V^(-1)·s^(-1),respectively,with 40%improvement relative to the regiorandom polymer.

Regioregular Non-Fused Polymerized Small Molecular Acceptors Enabling Efficient All-Polymer Solar Cells

Comprehensive Summary The regioregularity induced by the isomers of the end-groups has been widely recognized as a key factor that determines the photovoltaic properties of polymerized small molecular acceptors(PSMAs)in all-polymer solar cells(all-PSCs).However,the influence of regioregularity on the photovoltaic properties of non-fused PSMAs has not been explored yet.In this contribution,two regioregular non-fused PSMAs,PFBTz-T-γand PFBTz-T-δ,were synthesized for the first time by using the monomers with isomeric pure end-groups.Compared with PFBTz-T-δ,PFBTz-T-γhas more compact and more ordered packing in solid state,which results in a more red-shifted optical absorption and a higher electron mobility.More remarkably,PFBTz-T-γand PFBTz-T-δexhibited huge difference in photovoltaic performance in all-PSCs,which offered the power conversion efficiencies(PCEs)of 9.72%and 0.52%,respectively.Further studies have unveiled that the higher PCE of PFBTz-T-γis due to more efficient exciton dissociation,higher and more balanced electron/hole mobility,and less charge recombination as a result of favorable morphology of the blend film.This work demonstrates that the development of regioregular non-fused PSMAs by tuning the polymerization sites is an effective strategy for obtaining high-efficiency all-PSCs.

Donor-Acceptor Oligomers and Polymers Composed of Benzothiadiazole and 3-Hexylthiophene： Effect of Chain Length and Regioregularity

A series of donor-acceptor oligomer OBTThn （n = 1- 7） and polymer PBTThl and PBTTh2 composed of al- ternative 2,1,3-benzothiadiazole and 3-hexylthiophene have been designed and synthesized for the purpose of in- vestigation on the effect of chain length and side-chain regioregularity on their basic properties and photovoltaic performance. In the OBTThn oligomers and PBTThl polymer, all the hexyl side chains on thienyl units orient to- ward the same direction. Upon elongation of the chain length, the intramolecular charge transfer （ICT） absorption band in solution gradually redshifts from 398 nm for OBTThl to 505 nm for OBTThT, then to 512 nm for PBTThl polymer. Meanwhile, the HOMO energy level increases from -5.45 eV （OBTTh0 to -5.08 eV （OBTThT） and -5.09 eV （PBTThl）, and the LUMO energy level decreases from -3.11 eV （OBTTh0 to -3.30 eV （OBTThT） and -3.33 eV （PBTThl）, thus giving a smaller and smaller energy bandgap for higher oligomers and polymers. Theo- retical calculation suggests straight line-like backbone geometry for this series of oligomers and polymer. On the other hand, polymer PBTTh2 possesses a different side-chain regioregularity, in which every two neighbor hexyl side chains are arranged in different orienting direction. It is theoretically suggested to have curved line-like back- bone geometry. In solution, it shows similar photophysical and electrochemical properties as PBTThl. However in film state, it displays a less redshift in the ICT band as refer to that in solution than PBTThl. In combination with [6,6]-phenyl-C61-butyric acid methyl ester （PC61BM）, these oligomers and polymers were used as donor material to fabricate organic bulk heterojunction solar cells. Again, chain length-dependent device photovoltaic performance was observed. The device based on OBTTh4 showed a power conversion efficiency of 0.16%, while it increased to 0.36% and 0.49% for the devices based on OBTTh6 and PBTThb respectively. However, the side-chain regio- regularity has less influence on the device photovoltaic output since the device based on PBTTh~ displayed an effi- ciency of 0.52%, comparable to that of PBTThl.

合成方法对聚(3-己基噻吩)立构规整度的影响

采用化学氧化法、格式反应法、GRIM(Grignard Metathesis Method)法和超声辅助GRIM法、合成了不同立构规整度的聚3-己基噻吩(P3HT)。用GPC、紫外-可见光谱、红外光谱(FT-IR)和核磁共振谱(1H-NMR)对P3HT的分子结构和立构规整度进行了表征。结果表明,GRIM法合成的P3HT立构规整度高达93%,优于化学氧化法、格式反应法。在GRIM法的基础上引入超声辐照,使反应速率大幅度提高,反应30min后产率可达39%,同时P3HT的立构规整度得到进一步提高,高达到96%。

SYNTHESIS OF A HYPERBRANCHED POLY(AROYLARYLENE) CONTAINING TRIAZOLE AND FLUORENE FUNCTIONALITIES BY CLICK CHEMISTRY AND METAL-FREE,REGIOSELECTIVE POLYCYCLOTRIMERIZATION

A new bis(aroylacetylene) containing tfiazole and fluorene moieties is synthesized by click chemistry. Polycyclotrimerization of the monomer is catalyzed by piperidine in refluxed dioxane,furnishing a regioregular poly(aroylarylene) in a satisfactory yield.The hyperbranched structure of the polymer is characterized spectroscopically with satisfactory results.The polymer enjoys no metal detriment and is soluble in common organic solvents such as tetrahydrofuran (THF),chloroform,dichloromethane (DCM),and N,N-...

准分子激光照射对RR-P3HT薄膜形态影响

报告了波长248 nm准分子激光对RR-P3HT薄膜照射加工的实验结果.发现248 nm准分子激光对RR-P3HT薄膜材料的烧蚀机制既包含光化学作用也包含光热作用.烧蚀作用使RR-P3HT薄膜分光光谱发生了蓝移,并改变了滴涂法制备的RR-P3HT薄膜在基板上的配向.

利用Heck反应制备立构规整聚(3-己基噻吩)

采用Heck反应法合成了具有较高分子量和立构规整度的聚(3-己基噻吩)。研究了溶剂的种类及配比、相转移催化剂及催化剂的种类以及反应温度、反应时间对所得聚(3-己基噻吩)的分子量和规整度的影响。用凝胶色谱(GPC)和核磁共振谱(1HNMR)对聚(3-己基噻吩)的分子量及立构规整度进行了表征。用紫外-可见分光光度计和荧光分光光度计研究了聚(3-己基噻吩)的吸收光谱和发射光谱。结果表明,当溶剂为二甲基甲酰胺与四氢呋喃(DMF:THF=1:1)的混合溶剂,采用醋酸钯[用量为单体量的5%(摩尔分数)]为催化剂,四丁基溴化铵[用量为单体量的100%(摩尔分数)]为相转移催化剂时,在80℃下反应12h所得聚(3-己基噻吩)的分子量可达6700,立构规整度超过96%。

新型糖基聚合物的合成及其作为高效液相色谱手性固定相的应用(英文)

Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases(CSPs)for high performance liquid chromatography(HPLC).The regioregular polymer(poly-5)shows clear resolution ability for the racemate of cobalt(Ⅲ)acetylacetonate(Co(acac)3),whereas the corresponding regioirregular polymer(poly-3)does not show any chiral recognition for Co(acac)3.The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.

基于荧蒽酰亚胺的立构规整共轭高分子的合成与场效应晶体管性能

荧蒽是一种典型的具有高度平面结构的稠环芳烃,中心独特的五元环赋予了它缺电子特性,因此非常适合用于构筑稠环酰亚胺类受体砌块。然而,由于功能化位置受限,荧蒽酰亚胺砌块还未能成功用于共轭高分子的构建。本工作基于一种具有不对称结构的2,3-酰亚胺荧蒽砌块,成功构建了两个新型给受体(D-A)型共轭高分子,即无规结构的PF1以及立构规整结构的PF2,并详细表征了它们的光物理性质以及场效应晶体管器件性能。研究发现,PF2由于立构规整结构形成了相对有序的分子聚集以及更加优异的薄膜形貌,所制备的场效应晶体管器件表现出1.72×10^(-5)cm^(2)·V^(-1)·s^(-1)的空穴迁移率,而基于无规PF1制备的场效应晶体管则未能测出器件性能。本工作不仅表明2,3-酰亚胺荧蒽作为受体砌块在构建新型D-A型高分子半导体上具有一定的发展潜力,且进一步证实了分子规整性对分子堆积行为和光电性能的关键影响。

高分子有机场效应晶体管中半导体薄膜结晶行为及微观结构变化的研究

为了探索高分子有机场效应晶体管(OFET)中高分子自组织机理与电荷传输的关联性,采用同步辐射掠入射X射线衍射技术研究了高分子OFET中以高度区域规则的聚(3-己基噻吩)(RR-P3HT)为代表的半导体层的结晶行为及微观结构组织变化,及其引起的高分子半导体电荷传输机理.研究发现,采用自组装单分子层(SAMs)技术进行界面修饰,可以完善绝缘层与RR-P3HT半导体层之间的界面效果.SAMs的形成改善了界面,可以有效地控制上层RR-P3HT半导体层的结晶性及微观结构,使较多的噻吩环面垂直于衬底、得到π-π堆积方向平行于衬底的二维微晶粒薄片结构,这种微观结构有效地形成了二维共轭电荷传输通道,完善了在RR-P3HT工作层生长过程中的自组织机理;并且对于RR-P3HT半导体工作层来说,慢速生长过程比快速生长过程更有利于有效的二维共轭微晶粒薄片生长,更能完善RR-P3HT工作层生长过程中的自组织机理.

Polymerizing small molecular acceptors for efficient all-polymer solar cells

All-polymer solar cells(all-PSCs)have received attention due to their morphological stability under thermal and mechanical stresses.Currently,the highest reported power conversion efficiency of all-PSCs is over 17%,achieved by utilizing polymerized small molecular acceptors(PSMAs).However,the need for higher regiospecificity to avoid forming isomers during polymerization of SMAs still challenges the further applications of all-PSCs.From this perspective,we focus on some recent studies and highlight the importance of controlling the regioregularity of PSMAs.In particular,integrating PSMAs with regioregularity endows the polymer acceptors with good absorption,superior backbone ordering,and optimal blend morphology compared with those obtained from regiorandom one.Moreover,the distinctive features that are derived from these regioregular PSMAs,such as the possibility of repeatable synthesis and reproducible device performance,herald a brighter future for scaling-up and commercializing all-PSCs.We expect this integrated strategy will inspire researchers to devote more efforts to further narrow the efficiency gap between the PSCs based on SMAs and PSMAs.Finally,we discuss the existing challenges and future prospects of PSMAs as new platform for further advancing all-PSCs.

非溶剂掺杂完善自组织机理提升高度区域规则的(3-己基噻吩)有机场效应晶体管器件性能的研究

为了保证在低温加工及溶液制备的情况下,能够提升高度区域规则的聚(3-己基噻吩)(RR-P3HT)有机场效应晶体管(OFET)的器件性能,本文研究了室温下乙醇及乙腈非溶剂的掺杂,及其对高分子自组织机理与导致的RR-P3HTOFET电学性能的影响.实验发现,适量进行乙醇及乙腈非溶剂的掺杂,将促进RR-P3HT薄膜形成更多期望的微晶粒薄片结构,完善高分子自组织机理,导致RR-P3HTOFET电学性能的提升.实验表明,在RR-P3HT溶液中进行5%乙腈添加后,其器件场效应迁移率的值由原来的4.04×10-4cm2/V·s增加到3.39×10-3cm2/V·s,RR-P3HTOFET的场效应迁移率增强了大约8倍.而当乙醇及乙腈非溶剂掺杂浓度过量时,二维微晶粒结构的有序度降低,并且产生了明显的沉淀析出现象,薄膜呈现明显的龟裂现象,这样的沉淀物析出物在导电沟道里将作为缺陷存在,降低了RR-P3HT OFET的器件性能.

Effects of catalyst loading amount on the synthesis of poly（3-hexylthiophene） via externally initiated Kumada catalyst-transfer polycondensation

A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.

用于气相冰毒检测的区域规整的高通透聚合物

本文设计了区域规整的高通透性聚合物材料并应用于甲基苯丙胺(冰毒)蒸气的检测中。通过聚合物区域规整性的控制以及侧链上大位阻基团的引入,增强了材料通透性,并为气体分子增加了有效传感位点。另外,引入大位阻基团也能在一定程度上减少聚合物链间π-π堆叠造成的荧光自淬灭。此外,材料拥有良好的荧光量子效率和光稳定性。通过合成区域规整的高通透性聚合物,聚合物薄膜对胺类检测的传感都有所增强,其中,对甲基苯丙胺的蒸气检测材料的荧光增强达到了最高的106%,为甲基苯丙胺蒸气的荧光增强检测提供了新的思路。