The synthesis of key 4-alkyl-substituted 5-(trimethylsilyl)thiophene-2-boronic acid pinacol esters 3 allowed a simplified alkylthiophene catenation process to access bis-, ter-, quater-, and quinquethiophene π-bridges for the synthesis of acceptor–π-bridge-donor– π-bridge-acceptor (A–π-D–π-A) electron donor molecules. Based on the known benzodithiophene-terthiophene-rhodanine (BTR) material, the BXR series of materials, BMR (X = M, monothiophene), BBR (X = B, bithiophene), known BTR (X = T, terthiophene), BQR (X = Q, quaterthiophene), and BPR (X = P(penta), quinquethiophene) were synthesised to examine the influence of chromophore extension on the device performance and stability for OPV applications. The BTxR (x = 4, butyl, and x = 8, octyl) series of materials were synthesised by varying the oligothiophene π-bridge alkyl substituent to examine structure–property relationships in OPV device performance. The devices assembled using electron donors with an extended chromophore (BQR and BPR) are shown to be more thermally stable than the BTR containing devices, with un-optimized efficiencies up to 9.0% PCE. BQR has been incorporated as a secondary donor in ternary blend devices with PTB7-Th resulting in high-performance OPV devices with up to 10.7% PCE.
通过合成关键的4-烷基取代的5-(三甲基硅基)噻吩-2-硼酸皮纳科酯3,简化了烷基噻吩串联过程,以访问受体-π-桥-给体-π-桥-受体(A-π-D-π-A)电子给体分子的双噻吩、三噻吩、四噻吩和五噻吩π-桥。基于已知的苯并噻吩-三噻吩-罗丹明(BTR)材料,合成了BXR系列材料,BMR(X = M,单噻吩),BBR(X = B,双噻吩),已知的BTR(X = T,三噻吩),BQR(X = Q,四噻吩)和BPR(X = P(五噻),五噻吩),以研究色团扩展对OPV应用中器件性能和稳定性的影响。通过改变寡噻吩π-桥烷基取代基合成了BTxR(x = 4,丁基,x = 8,辛基)系列材料,以研究结构-性能关系在OPV器件性能中的作用。使用具有扩展色团(BQR和BPR)的电子给体组装的器件比含有BTR的器件更加热稳定,未经优化的效率高达9.0% PCE。在三元混合物器件中,BQR已作为次级给体与PTB7-Th结合,导致高性能OPV器件的效率高达10.7% PCE。