Block Junction-Functionalized All-Conjugated Donor-Acceptor Block Copolymers.
Block Junction-Functionalized All-Conjugated Donor-Acceptor Block Copolymers.
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DOI：
10.1021/acsami.8b18608
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发表时间：
2018-12
影响因子：
9.5
通讯作者：
Fritz Nübling;Thomas R. Hopper;Brooke Kuei;H. Komber;Viktoriia Untilova;Simon B. Schmidt;M. Brinkmann;E. Gomez;A. Bakulin;M. Sommer
中科院分区：
文献类型：
--
作者：
Fritz Nübling;Thomas R. Hopper;Brooke Kuei;H. Komber;Viktoriia Untilova;Simon B. Schmidt;M. Brinkmann;E. Gomez;A. Bakulin;M. Sommer
结官能化的供体-受体（D-A）嵌段共聚物（BCP）使得能够对激子器件（例如太阳能电池）中的界面电荷动力学进行空间和电子控制。在这里，我们提出的设计，合成，形态，和电子特性的块结功能化，所有共轭，全结晶D-A BCP。聚（3-己基噻吩）（P3 HT）、单个噻吩基化的二酮基吡咯并吡咯（Th xDPPTh x，x = 1或2）单元和聚{[ N，N ′-双（2-辛基十二烷基）-萘-1，4，5，8-双（二甲酰亚胺）-2，6-二基]- alt-5，5 ′-（2，2 ′-联噻吩）}（PNDIT 2）分别用作供体、界面单元和受体。几乎所有的C-C偶联步骤都是通过C-H活化完成的。大分子试剂H-P3 HT-Th xDPPTh x的合成（其中x确定其C-H反应性）是合成H-P3 HT-Th xDPPTh x-嵌段-PNDIT 2型的各种BCP的关键。形态是由量热法，透射电子显微镜（TEM），和薄膜散射的组合。P3 HT和PNDIT 2的嵌段共聚物结晶度降低，表明结晶受阻。长周期lp在TEM中是不可见的，但在共振软X射线散射实验中出现在lp ~ 60 nm的长度尺度上。H-P3 HT-Th xDPPTh x的光致发光表明激发能有效地转移到DPP链端，但在BCP膜中被淬灭。瞬态吸收和泵推光电流光谱揭示了孪晶复合（GR）作为主要的损耗通道，在所制备的BCP膜独立的结功能化。熔融退火增加GR的结晶度低，定义不明确的接口的结果，并另外改变PNDIT 2从正面到边缘上的骨干取向。这些形态的影响主导太阳能电池的性能，并导致不敏感的存在下的块结。
Junction-functionalized donor-acceptor (D-A) block copolymers (BCPs) enable spatial and electronic control over interfacial charge dynamics in excitonic devices such as solar cells. Here, we present the design, synthesis, morphology, and electronic characterization of block junction-functionalized, all-conjugated, all-crystalline D-A BCPs. Poly(3-hexylthiophene) (P3HT), a single thienylated diketopyrrolopyrrole (Th xDPPTh x, x = 1 or 2) unit, and poly{[ N, N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]- alt-5,5'-(2,2'-bithiophene)} (PNDIT2) are used as donor, interfacial unit, and acceptor, respectively. Almost all C-C coupling steps are accomplished by virtue of C-H activation. Synthesis of the macroreagent H-P3HT-Th xDPPTh x, with x determining its C-H reactivity, is key to the synthesis of various BCPs of type H-P3HT-Th xDPPTh x- block-PNDIT2. Morphology is determined from a combination of calorimetry, transmission electron microscopy (TEM), and thin-film scattering. Block copolymer crystallinity of P3HT and PNDIT2 is reduced, indicating frustrated crystallization. A long period lp is invisible from TEM, but shows up in resonant soft X-ray scattering experiments at a length scale of lp ∼ 60 nm. Photoluminescence of H-P3HT-Th xDPPTh x indicates efficient transfer of the excitation energy to the DPP chain end, but is quenched in BCP films. Transient absorption and pump-push photocurrent spectroscopies reveal geminate recombination (GR) as the main loss channel in as-prepared BCP films independent of junction functionalization. Melt annealing increases GR as a result of the low degree of crystallinity and poorly defined interfaces and additionally changes backbone orientation of PNDIT2 from face-on to edge-on. These morphological effects dominate solar cell performance and cause an insensitivity to the presence of the block junction.