We report the design, synthesis, and properties of a novel type of donor (D)‐acceptor (A) polymer, poly(3‐(([2,2′:5′,2′′‐terthiophen]‐3‐yl‐5,5“‐diyl)methylene)‐1‐(2‐octyldodecyl)indolin‐2‐one) (PTIBT), with a donor backbone and acceptor side chains (Type II D‐A polymer) as donor for organic solar cells (OSCs) as opposed to the conventional D‐A polymers having both donor and acceptor units on backbone (Type I D‐A polymers). PTIBT having a backbone consisting of thiophene donor units and side chains containing indolin‐2‐one acceptor units was synthesized very conveniently in three steps. This polymer has a high dielectric constant of 7.70, which is beneficial for the exciton diffusion and dissociation in the active blend layer in an OSC. In addition, PTIBT was found to have a low‐lying HOMO energy level of −5.41 eV and a wide band gap of 1.80 eV in comparison to its counterpart Type I D‐A polymer. In organic thin film transistors (OTFTs), PTIBT showed typical p‐type semiconductor performance with hole mobilities of up to 1.81×10⁻² cm² V⁻¹ s⁻¹. When PTIBT and ITIC were used as donor and acceptor to form a blend active layer, the best OSC device showed a J_SC of 15.19 mAcm⁻², a V_OC of 0.66 V, and a fill factor of 0.57, resulting in a power conversion efficiency (PCE) of up to 5.72%.

中文翻译：

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具有供体骨干-受体侧链结构的D-A聚合物，用于有机太阳能电池

我们报告了新型供体（D）-受体（A）聚合物poly（3-（（[[2,2'：5'，2''-terthiophen] -3-yl -5,5“-二基）亚甲基）-1-（2-辛基十二烷基）吲哚-2--1（PTIBT），带有供体主链和受体侧链（II D-A型聚合物），作为有机太阳能电池的供体（OSC）与在主链上同时具有供体和受体单元的常规D-A聚合物（类型ID-A聚合物）相反。通过三个步骤非常方便地合成了具有由噻吩供体单元和含吲哚-2-1-2受体单元侧链组成的主链的PTIBT。该聚合物具有7.70的高介电常数，这对于OSC中的活性共混层中的激子扩散和解离是有利的。此外，发现PTIBT的HOMO能级较低，为-5.41 eV，宽带隙为1。与其对应的ID-A型聚合物相比为80 eV。在有机薄膜晶体管（OTFT）中，PTIBT表现出典型的p型半导体性能，空穴迁移率高达1.81×10^-2  cm ²  V ^-1  s ^-1。当将PTIBT和ITIC用作施主和受主以形成混合有源层时，最佳OSC器件的J _SC为15.19 mAcm ^-2，V _OC为0.66 V，填充系数为0.57，导致功率转换效率（PCE）高达5.72％。