Two new bithiophene derivatives named as 5, 5-bis(p-N,N-dimethylaminostyryl)-2, 2 -bithiophene (BMSBT), and 5, 5-bis(p-N,N-diethylaminostyryl)-2, 2-bithiophene (BESBT) have been synthesized. Both compounds can emit s...Two new bithiophene derivatives named as 5, 5-bis(p-N,N-dimethylaminostyryl)-2, 2 -bithiophene (BMSBT), and 5, 5-bis(p-N,N-diethylaminostyryl)-2, 2-bithiophene (BESBT) have been synthesized. Both compounds can emit strong single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) with the emission peaks around ~560 nm and with the lifetime of ~1ns.展开更多
Two polymer donor materials,namely pBDT-BTI-EH and pBDT-BTI-ME,were synthesized by copoly-merizing benzodithiophene(BDT)unit with bithiophene imide(BTI)unit containing 2-ethylhexyl and methyl alkyl side chains,respect...Two polymer donor materials,namely pBDT-BTI-EH and pBDT-BTI-ME,were synthesized by copoly-merizing benzodithiophene(BDT)unit with bithiophene imide(BTI)unit containing 2-ethylhexyl and methyl alkyl side chains,respectively.Compared to pBDT-BTI-EH∶Y6 based organic solar cells(OSCs),the pBDT-BTI-ME∶Y6-based device exhibited higher charge mobilities,reduced charge recombination,more efficient exciton dissociation,and favorable film morphology,which leaded to increased short current density(Jsc),fill factor(FF)and thus a significant improvement in power conversion efficiency(PCE)from 9.31%to 15.69%.展开更多
In this article,three novel and simple molecular structure with donor-acceptor(D-A) type copolymers via only head-to-head alkoxy(OR) and/or alkylthio(SR) side chains onto the bithiophene(BT) as donor units and fluorin...In this article,three novel and simple molecular structure with donor-acceptor(D-A) type copolymers via only head-to-head alkoxy(OR) and/or alkylthio(SR) side chains onto the bithiophene(BT) as donor units and fluorinated benzotriazole(FBTA) as acceptor unit,namely,PBTOR-FBTA,PBTOSR-FBTA and PBTSRFBTA,were successfully designed and synthesized.The impacts of sulfur-oxygen(S…O) or sulfur-sulfur(S-S) noncovalent interactions on their physicochemical properties,molecular stacking,carrier mobility,morphologies of blend films,as well as their photovoltaic performance were deeply and systematically studied.The introduction of SR side-chains suddenly lowered the highest occupied molecular orbital(HOMO) energy levels,blue-shifted absorption,enhanced π-π stacking,as well as improved morphology of the photoactive layer blends in comparison with the re ference polymer without SR side-chain.Polymer solar cells(PSCs) were fabricated to estimate their photovoltaic performance of the polymers.Under an optimized blend ratio of PBTSR-FBTA:PC71BM(1:0.8,w/w),the PBTSR-FBTAbased device exhibits a higher power conversion efficiency(PCE) of 6.25%,which is about 3.34 and 1.87 folds than that of the PBTOR-FBTA and PBTOSR-FBTA-based devices,respectively.Our research results demonstrate that the modification of the simple and low-cost SR side chains is an effective strategy to improve the photovoltaic performance of the polymers.展开更多
Bithiophene imide (BTI)-based polymers have been promising photovoltaic materials due to their high mobility and tunable energy levels. However, BTI polymers have rarely been revisited since organic solar cells (OSCs)...Bithiophene imide (BTI)-based polymers have been promising photovoltaic materials due to their high mobility and tunable energy levels. However, BTI polymers have rarely been revisited since organic solar cells (OSCs) entered the era of non-fullerene electron acceptors (NFEA) likely owing to their incompatibility with NFEAs. Herein, fine-tuning the aggregation and orientation of BTI-based donor-π-acceptor (D-π-A) polymer donors was achieved by incorporating the linear n-octyl group into thiophene π-bridge. The resulting polymer donor G15 shows excellent compatibility with NFEA L15 (polymer acceptor). The G15-based all-polymer OSCs achieve high power conversion efficiency of 15.17%. This is significantly higher than that (< 5%) of its analogue with isomerized branched alkyl chains and also among the highest values for all-polymer OSCs. The results highlight that well-tailored BTI polymer donors are attractive photovoltaic materials for further exploration in non-fullerene organic solar cells.展开更多
基金This work is supported by the National Natural Science Foundation of China(No.20172034)grant for State Key Program of China.
文摘Two new bithiophene derivatives named as 5, 5-bis(p-N,N-dimethylaminostyryl)-2, 2 -bithiophene (BMSBT), and 5, 5-bis(p-N,N-diethylaminostyryl)-2, 2-bithiophene (BESBT) have been synthesized. Both compounds can emit strong single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) with the emission peaks around ~560 nm and with the lifetime of ~1ns.
文摘Two polymer donor materials,namely pBDT-BTI-EH and pBDT-BTI-ME,were synthesized by copoly-merizing benzodithiophene(BDT)unit with bithiophene imide(BTI)unit containing 2-ethylhexyl and methyl alkyl side chains,respectively.Compared to pBDT-BTI-EH∶Y6 based organic solar cells(OSCs),the pBDT-BTI-ME∶Y6-based device exhibited higher charge mobilities,reduced charge recombination,more efficient exciton dissociation,and favorable film morphology,which leaded to increased short current density(Jsc),fill factor(FF)and thus a significant improvement in power conversion efficiency(PCE)from 9.31%to 15.69%.
基金financially supported by grants from the National Natural Science Foundation of China(Nos.51573154,51673031)The Natural Science Foundation of Jiangsu Higher Institutions of China(No.18KJA480001)+2 种基金the Youth Science and Technology Foundation of Sichuan Province(No.2013JQ0032)the key Laboratory of Environment-Friendly Chemistry and Applications of Ministry of Education(No.2018HJYH01)the Natural Science Foundation of Jiangsu Province(No.BK20141151)。
文摘In this article,three novel and simple molecular structure with donor-acceptor(D-A) type copolymers via only head-to-head alkoxy(OR) and/or alkylthio(SR) side chains onto the bithiophene(BT) as donor units and fluorinated benzotriazole(FBTA) as acceptor unit,namely,PBTOR-FBTA,PBTOSR-FBTA and PBTSRFBTA,were successfully designed and synthesized.The impacts of sulfur-oxygen(S…O) or sulfur-sulfur(S-S) noncovalent interactions on their physicochemical properties,molecular stacking,carrier mobility,morphologies of blend films,as well as their photovoltaic performance were deeply and systematically studied.The introduction of SR side-chains suddenly lowered the highest occupied molecular orbital(HOMO) energy levels,blue-shifted absorption,enhanced π-π stacking,as well as improved morphology of the photoactive layer blends in comparison with the re ference polymer without SR side-chain.Polymer solar cells(PSCs) were fabricated to estimate their photovoltaic performance of the polymers.Under an optimized blend ratio of PBTSR-FBTA:PC71BM(1:0.8,w/w),the PBTSR-FBTAbased device exhibits a higher power conversion efficiency(PCE) of 6.25%,which is about 3.34 and 1.87 folds than that of the PBTOR-FBTA and PBTOSR-FBTA-based devices,respectively.Our research results demonstrate that the modification of the simple and low-cost SR side chains is an effective strategy to improve the photovoltaic performance of the polymers.
基金support from the Songshan Lake Mate-rials Laboratory(2021SLABFK03)This work is supported by the National Natural Science Foundation of China(52173172,52173171,and 21801124)+4 种基金the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province(2021B1515020027)the Guangdong Basic and Applied Basic Research Foundation(2021A1515110892)the China Postdoctoral Science Foundation(2021M700062)the Shenzhen Science and Technology Innovation Commission JCYJ202103243104813035 and JCYJ20180504165709042)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology).
文摘Bithiophene imide (BTI)-based polymers have been promising photovoltaic materials due to their high mobility and tunable energy levels. However, BTI polymers have rarely been revisited since organic solar cells (OSCs) entered the era of non-fullerene electron acceptors (NFEA) likely owing to their incompatibility with NFEAs. Herein, fine-tuning the aggregation and orientation of BTI-based donor-π-acceptor (D-π-A) polymer donors was achieved by incorporating the linear n-octyl group into thiophene π-bridge. The resulting polymer donor G15 shows excellent compatibility with NFEA L15 (polymer acceptor). The G15-based all-polymer OSCs achieve high power conversion efficiency of 15.17%. This is significantly higher than that (< 5%) of its analogue with isomerized branched alkyl chains and also among the highest values for all-polymer OSCs. The results highlight that well-tailored BTI polymer donors are attractive photovoltaic materials for further exploration in non-fullerene organic solar cells.
