Two benzo[1,2-b:4,5-b￠]dithiophene(BDT)-based small molecule(SM) donor materials with identical conjugated backbones but different substitution groups, named as DRTB-O and DRTB-T, were well explored to demonstrate th...Two benzo[1,2-b:4,5-b￠]dithiophene(BDT)-based small molecule(SM) donor materials with identical conjugated backbones but different substitution groups, named as DRTB-O and DRTB-T, were well explored to demonstrate the influence of the replacement of alkoxy with alkylthienyl on their photovoltaic properties in fullerene-based and fullerene-free organic solar cells(OSCs). The study shows that the two SM donors possess similar absorption spectra and energy levels but different crystalline structures in solid films. The carrier transport property and phase separation morphologies of the blend films have also been fully investigated.By employing PC71 BM as the acceptor, the power conversion efficiency(PCE) of DRTB-O:PC71BM and DRTB-T:PC71BM based devices were 4.91% and 7.08%, respectively. However, by blending with IDIC, the two SM donors exhibited distinctly different photovoltaic properties in fullerene-free OSCs, and the PCE of DRTB-O:IDIC and DRTB-T:IDIC based devices were 0.15% and9.06%, respectively. These results indicate that the replacement of alkoxyl with alkylthienyl in designing SM donor materials plays an important role in the application of fullerene-free OSCs.展开更多
A new benzodithiophene （BDT）-alt-fluorobenzotriazole （FBTA） D-A copolymer J40 was designed and synthesized by introducing 2-octyldodecyloxy side chains on its BDT units, for expanding the family of the BDT- alt-FB...A new benzodithiophene （BDT）-alt-fluorobenzotriazole （FBTA） D-A copolymer J40 was designed and synthesized by introducing 2-octyldodecyloxy side chains on its BDT units, for expanding the family of the BDT- alt-FBTA-based copolymers and investigating the side chain effect on the photovoltaic performance of the polymer in non-fullerene polymer solar cells （PSCs）. J40 exhibits complementary absorption spectra and matched electronic energy levels with the n-type organic semiconductor （n-OS） （3,9-bis（2-methylene-（3-（1,1-dicyanomethylene）-indanone））-5,5,11,11-tetrakis（4-hexylphenyl）-dithieno[2,3-d：2＇,3＇-d＇]-s- indaceno[1,2-b：5,6-b＇]dithiophene） （ITIC） acceptor, and was used as polymer donor in the non-fullerene PSCs with ITIC as acceptor. The power conversion efficiency （PCE） of the PSCs based on J40：ITIC （1：1, w/w） with thermal annealing at 120 ~C for l0 min reached 6.48% with a higher open-circuit voltage （Voc） of 0.89 V. The high Voc of the PSCs is benefitted from the lower-lying highest occupied molecular orbital （HOMO） energy level of J40. Although the photovoltaic performance of the polymer J40 with alkoxy side chain is lower than that of J60 and J61 with alkylthio-thienyl conjugated side chains, the PCE of 6.48% for the J40-based device is still a relatively higher photovoltaic efficiency in the non-fullerene PSCs reported so far. The results indicate that the family of the BDT-alt-FBTA-based D-A copolymers are high performance polymer donor materials for non-fullerene PSCs and the side chain engineering plays an important role in the design of high performance polymer donors in the non-fullerene PSCs.展开更多
Based on the J-aggregation mechanism of α-aryl/alkoxy-substituted zinc phthalocyanines(Pcs) in non-coordinating solvents, two novel azobenzene-phthalocyanine dyads (3-azo-ZnPc and 4-azo-ZnPc) were synthesized with th...Based on the J-aggregation mechanism of α-aryl/alkoxy-substituted zinc phthalocyanines(Pcs) in non-coordinating solvents, two novel azobenzene-phthalocyanine dyads (3-azo-ZnPc and 4-azo-ZnPc) were synthesized with the aim of developing Pc compounds whose ability to form J-aggregation could be photo-modulated. It was found that 3-azo-ZnPc in chloroform could be effectively photo-controlled in a wide range. This phenomenon could be explained by the changes in the geometry and dipole moment of azobenzene during the photo-isomerization process. 4-azo-ZnPc did not have this ability at all, with or without UV light illumination. The positions of the oxygen atoms to which the aryl/alkoxy substitution was attached relatively were found important in determining the aggregation ability.展开更多
基金supported by the Ministry of Science and Technology of China (2014CB643501)the National Natural Science Foundation of China (21325419, 51373181, 91333204, 91633301)
文摘Two benzo[1,2-b:4,5-b￠]dithiophene(BDT)-based small molecule(SM) donor materials with identical conjugated backbones but different substitution groups, named as DRTB-O and DRTB-T, were well explored to demonstrate the influence of the replacement of alkoxy with alkylthienyl on their photovoltaic properties in fullerene-based and fullerene-free organic solar cells(OSCs). The study shows that the two SM donors possess similar absorption spectra and energy levels but different crystalline structures in solid films. The carrier transport property and phase separation morphologies of the blend films have also been fully investigated.By employing PC71 BM as the acceptor, the power conversion efficiency(PCE) of DRTB-O:PC71BM and DRTB-T:PC71BM based devices were 4.91% and 7.08%, respectively. However, by blending with IDIC, the two SM donors exhibited distinctly different photovoltaic properties in fullerene-free OSCs, and the PCE of DRTB-O:IDIC and DRTB-T:IDIC based devices were 0.15% and9.06%, respectively. These results indicate that the replacement of alkoxyl with alkylthienyl in designing SM donor materials plays an important role in the application of fullerene-free OSCs.
基金supported by the National Basic Research Program of China(2014CB643501)the National Natural Science Foundation of China(91433117,91333204,21374124)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12030200)
文摘A new benzodithiophene （BDT）-alt-fluorobenzotriazole （FBTA） D-A copolymer J40 was designed and synthesized by introducing 2-octyldodecyloxy side chains on its BDT units, for expanding the family of the BDT- alt-FBTA-based copolymers and investigating the side chain effect on the photovoltaic performance of the polymer in non-fullerene polymer solar cells （PSCs）. J40 exhibits complementary absorption spectra and matched electronic energy levels with the n-type organic semiconductor （n-OS） （3,9-bis（2-methylene-（3-（1,1-dicyanomethylene）-indanone））-5,5,11,11-tetrakis（4-hexylphenyl）-dithieno[2,3-d：2＇,3＇-d＇]-s- indaceno[1,2-b：5,6-b＇]dithiophene） （ITIC） acceptor, and was used as polymer donor in the non-fullerene PSCs with ITIC as acceptor. The power conversion efficiency （PCE） of the PSCs based on J40：ITIC （1：1, w/w） with thermal annealing at 120 ~C for l0 min reached 6.48% with a higher open-circuit voltage （Voc） of 0.89 V. The high Voc of the PSCs is benefitted from the lower-lying highest occupied molecular orbital （HOMO） energy level of J40. Although the photovoltaic performance of the polymer J40 with alkoxy side chain is lower than that of J60 and J61 with alkylthio-thienyl conjugated side chains, the PCE of 6.48% for the J40-based device is still a relatively higher photovoltaic efficiency in the non-fullerene PSCs reported so far. The results indicate that the family of the BDT-alt-FBTA-based D-A copolymers are high performance polymer donor materials for non-fullerene PSCs and the side chain engineering plays an important role in the design of high performance polymer donors in the non-fullerene PSCs.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20572059, 20502013 and 20773077)National Key Fundamental Research Program (Grant No. 2007CB808000)
文摘Based on the J-aggregation mechanism of α-aryl/alkoxy-substituted zinc phthalocyanines(Pcs) in non-coordinating solvents, two novel azobenzene-phthalocyanine dyads (3-azo-ZnPc and 4-azo-ZnPc) were synthesized with the aim of developing Pc compounds whose ability to form J-aggregation could be photo-modulated. It was found that 3-azo-ZnPc in chloroform could be effectively photo-controlled in a wide range. This phenomenon could be explained by the changes in the geometry and dipole moment of azobenzene during the photo-isomerization process. 4-azo-ZnPc did not have this ability at all, with or without UV light illumination. The positions of the oxygen atoms to which the aryl/alkoxy substitution was attached relatively were found important in determining the aggregation ability.
