%0 Journal Article %1 zhang2018thermally %A Zhang, Yannan %A Xu, Yalong %A Ford, Michael J. %A Li, Fangchao %A Sun, Jianxia %A Ling, Xufeng %A Wang, Yongjie %A Gu, Jinan %A Yuan, Jianyu %A Ma, Wanli %D 2018 %I Wiley Online Library %J Advanced Energy Materials %K electron_acceptors nonfullerene organic stability %N 18 %R 10.1002/aenm.201800029 %T Thermally Stable All‐Polymer Solar Cells with High Tolerance on Blend Ratios %U https://doi.org/10.1002/aenm.201800029 %V 8 %X Tuning the blend composition is an essential step to optimize the power conversion efficiency (PCE) of organic bulk heterojunction (BHJ) solar cells. PCEs from devices of unoptimized donor:acceptor (D:A) weight ratio are generally significantly lower than optimized devices. Here, two high‐performance organic nonfullerene BHJ blends PBDB‐T:ITIC and PBDB‐T:N2200 are adopted to investigate the effect of blend ratio on device performance. It is found that the PCEs of polymer‐polymer (PBDB‐T:N2200) blend are more tolerant to composition changes, relative to polymer‐molecule (PBDB‐T:ITIC) devices. In both systems, short‐circuit current density (Jsc) is tracked closely with PCE, indicating that exciton dissociation and transport strongly influence PCEs. With dilute acceptor concentrations, polymer‐polymer blends maintain high electron mobility relative to the polymer‐molecule blends, which explains the dramatic difference in PCEs between them as a function of D:A blend ratio. In addition, polymer‐polymer solar cells, especially at high D:A blend ratio, are stable (less than 5% relative loss) over 70 d under continuous heating at 80 °C in a glovebox without encapsulation. This work demonstrates that all‐polymer solar cells show advantage in operational lifetime under thermal stress and blend‐ratio resilience, which indicates their high potential for designing of stable and scalable solar cells. Based on two representative and high performance organic nonfullerene bulk heterojunction blends, PBDB‐T:ITIC and PBDB‐T:N2200, the effect of blend ratio on device performance and the relevant device stability is investigated in‐depth. Solar cell devices incorporating polymer–polymer blends exhibit stable device performance in a wide range of blend ratios and excellent stability under dark and thermal stress.

@article{zhang2018thermally, abstract = {Tuning the blend composition is an essential step to optimize the power conversion efficiency (PCE) of organic bulk heterojunction (BHJ) solar cells. PCEs from devices of unoptimized donor:acceptor (D:A) weight ratio are generally significantly lower than optimized devices. Here, two high‐performance organic nonfullerene BHJ blends PBDB‐T:ITIC and PBDB‐T:N2200 are adopted to investigate the effect of blend ratio on device performance. It is found that the PCEs of polymer‐polymer (PBDB‐T:N2200) blend are more tolerant to composition changes, relative to polymer‐molecule (PBDB‐T:ITIC) devices. In both systems, short‐circuit current density (Jsc) is tracked closely with PCE, indicating that exciton dissociation and transport strongly influence PCEs. With dilute acceptor concentrations, polymer‐polymer blends maintain high electron mobility relative to the polymer‐molecule blends, which explains the dramatic difference in PCEs between them as a function of D:A blend ratio. In addition, polymer‐polymer solar cells, especially at high D:A blend ratio, are stable (less than 5% relative loss) over 70 d under continuous heating at 80 °C in a glovebox without encapsulation. This work demonstrates that all‐polymer solar cells show advantage in operational lifetime under thermal stress and blend‐ratio resilience, which indicates their high potential for designing of stable and scalable solar cells. Based on two representative and high performance organic nonfullerene bulk heterojunction blends, PBDB‐T:ITIC and PBDB‐T:N2200, the effect of blend ratio on device performance and the relevant device stability is investigated in‐depth. Solar cell devices incorporating polymer–polymer blends exhibit stable device performance in a wide range of blend ratios and excellent stability under dark and thermal stress.}, added-at = {2018-07-04T14:05:40.000+0200}, author = {Zhang, Yannan and Xu, Yalong and Ford, Michael J. and Li, Fangchao and Sun, Jianxia and Ling, Xufeng and Wang, Yongjie and Gu, Jinan and Yuan, Jianyu and Ma, Wanli}, biburl = {https://www.bibsonomy.org/bibtex/265e2eb2417d0d33d6502ebe4ce945b34/bretschneider_m}, doi = {10.1002/aenm.201800029}, interhash = {90002e2ffc2880cebcbeb2300b0f0b1f}, intrahash = {65e2eb2417d0d33d6502ebe4ce945b34}, issn = {1614-6832}, journal = {Advanced Energy Materials}, keywords = {electron_acceptors nonfullerene organic stability}, month = {6}, number = 18, publisher = {Wiley Online Library}, timestamp = {2018-07-04T14:05:40.000+0200}, title = {Thermally Stable All‐Polymer Solar Cells with High Tolerance on Blend Ratios}, url = {https://doi.org/10.1002/aenm.201800029}, volume = 8, year = 2018 }