Synthesis and photovoltaic properties of new small molecules with rhodanine derivative as the end-capped blocks

Abstract

a b s t r a c tTwo new acceptor-donor-acceptor (A-D-A) type small molecules DCAO3TIDT and DCNR3TIDT, with 4,4,9,9-tetrakis(4-(dodecyloxy)phenyl)-4,9-dihydro-s-indaceno-[1,2-b:5,6-b 0 ]dithiophene (IDT) as the core group and 2-ethylhexyl cyanoacetate (CAO) and 2-(1,1-dicyanomethylene)-3-octyl rhodanine (CNR) as different end-capped blocks, have been designed and synthesized. Both of them have been employed as donor for solutionprocessed bulk hetero-junction (BHJ) organic solar cells (OSCs). The two compounds showed deep highest occupied molecular orbital (HOMO) energy levels ($À5.30 eV) and strong absorption. The DCAO3TIDT and DCNR3TIDT with PC 71 BM as acceptor based BHJ solar cell devices showed short circuit current density (J sc ) of 6.93 mA/cm 2 and 8.59 mA/ cm 2 , power conversion efficiency (PCE) of 3.34% and 4.27%, respectively, and with almost same open-circuit voltage ($0.93 V), under the illumination of AM 1.5 G, 100 mW/cm 2 . The high J sc for DCNR3TIDT could result from its wider and red-shifted absorption than that of DCAO3TIDT, which was probably induced by the end-capped block rhodanine derivative. The results demonstrate that the end group would be taken into full account when designing new solution-processed small molecules, which is an important factor to determine their photovoltaic properties.

Synthesis of Polyacrylate‐Based Chalcone Containing Different Donor Moieties and Studies on their Optical, Electrochemical, and Thermal Properties

“…More precise, their applications in polymer light-emitting diodes (PLEDs), polymer solar cells (PSCs), and organic field-effect transistors (OFETs) offer opportunities for the urgent need for a renewable energy supply as well as the development of display and information technologies. [1][2][3] Chemists can design and synthesize a variety of conjugated polymers with different architectures and functional moieties to get efficient electronic devices, it is necessary to tune their properties such as band gap, molecular energy level, solubility, and light harvesting. Band gap engineering and molecular energy-level optimizations are of great importance in advancing toward a highly efficient polymer for LED and photovoltaic (PV) devices.…”

Progress of Organic Photovoltaic Materials Based on Indacenodithiophene and Its Derivatives

“…在 IDT 小分子材料主链上引入噻吩单元, 有助于共 轭程度的加强, 这在前面聚合物的部分有所介绍. 为探 索 IDT 小分子中共聚噻吩对材料性能的影响, 我们比较 由侯剑辉课题组 [55] 合成的结构相似的分子 51 和苏仕健 课题组 [56] - [60] 分子间的 π-π 电子堆积, 而这些都能提高载流子迁移率.…”

“…当从二噻吩到三噻吩延长 π 桥时, J sc 增长了很多. 后来阳仁强课题组[60] 对氰酸酯和罗丹宁分子进行了更 加深入的讨论. 为了减少空间位阻, 在 63 和 64 分子中 在联三噻吩上没有其他侧链.…”

Design of donor–acceptor–donor (D–A–D) type small molecule donor materials with efficient photovoltaic parameters

“…Over the past decade, considerable progress has been made primarily in efficient material designing, morphology of device, modification of device, and in device engineering . Optimized power conversion efficiency (PCE) of polymer‐based photovoltaics (P‐PVs) is more than 9% in single junction devices and PCE of 10.6% is reported for tandem devices, whereas a PCE of 9.30% (certified 8.995%) has been reported for small molecule‐based photovoltaics (SM‐PVs) . SM‐PVs have distinct merits including higher open circuit voltage Voc, high reproducibility, higher hole mobility, more reproducible fabrication‐protocol .…”