摘要
A novel A-D-A （acceptor-donor-acceptor） type non-fullerene small molecule, A201, consisting of an asymmetric thieno[1,2-b]indaceno[5,6-b＇lthienothiophene （TITI＇） unit as middle D part and 2-（3-oxo-2, 3-dihydroinden-l-ylidene） malononitrile （IC） groups as end-capped A parts was designed and synthesized. The asymmetric TITT building block showed a higher dipole moment of 0.85 Debye （1 Debye = 3.33564 × 10^-3μcm） compared with the symmetric analogues of indacenodithiophene （IDT） and indacenodithieno[3,2-b]thiophene （IDTr） of 0.098 and 0.13 Debye, respectively. The solution-processed bulk heterojunction solar cells using a benzotriazole （BTA）-based polymer of J71 as donor and A201 as acceptor, showed a power conversion efficiency （PCE） of 9.36% with an open-circuit voltage （Voc） of 0.88 V, a short-circuit current Use） of 13.15 mA cm^-2, and a fill factor （FF） of 0.B7, under the illumination of AM 1.5G at 100 mW cm^-2. The high PCE of this material combination could be attributed to its broad absorption spectrum and the high hole mobility （#h） and electron mobility （μh） of 9.56 × 10^-4 and 5.1× 10^-4 cm^2 V^-1 s^-1, respectively. These results indicate that the asymmetric electron-donating segments are promising to construct A-D-A type small molecular acceptors, which could largely enhance the diversity of building blocks to design photovoltaic materials.
A novel A-D-A(acceptor-donor-acceptor)type non-fullerene small molecule,A201,consisting of an asymmetric thieno[1,2-b]indaceno[5,6-b^0]thienothiophene(TITT)unit as middle D part and 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC)groups as end-capped A parts was designed and synthesized.The asymmetric TITT building block showed a higher dipole moment of 0.85 Debye(1 Debye=3.33564?10^(à30)cm)compared with the symmetric analogues of indacenodithiophene(IDT)and indacenodithieno[3,2-b]thiophene(IDTT)of 0.098 and 0.13 Debye,respectively.The solution-processed bulk heterojunction solar cells using a benzotriazole(BTA)-based polymer of J71 as donor and A201 as acceptor,showed a power conversion efficiency(PCE)of 9.36%with an open-circuit voltage(V_(oc))of0.88 V,a short-circuit current(J_(sc))of 13.15 m A cm^(à2),and a fill factor(FF)of 0.67,under the illumination of AM 1.5G at 100 m W cm^(à2).The high PCE of this material combination could be attributed to its broad absorption spectrum and the high hole mobility(l_h)and electron mobility(l_e)of 9.56?10^(à4)and 5.17?10^(à4)cm^2V^(à1)s^(à1),respectively.These results indicate that the asymmetric electron-donating segments are promising to construct A-D-A type small molecular acceptors,which could largely enhance the diversity of building blocks to design photovoltaic materials.
基金
support from the Key Research Program of Frontier Sciences,Chinese Academy of Sciences (QYZDB-SSWSLH033)
the National Key Research and Development Program of China (2017YFA0206600)
the National Natural Science Foundation of China (51673048,51473040,21504019,51773046,and 21602040)
the National Natural Science Foundation of Beijing (2162045)
