The open-circuit voltage(V_(oc))of classical photovoltaic polymers,such as P3HT and PTB7-Th,are always restricted when combining with fullerene derivatives,due to the difficulty of modulating the energy levels of full...The open-circuit voltage(V_(oc))of classical photovoltaic polymers,such as P3HT and PTB7-Th,are always restricted when combining with fullerene derivatives,due to the difficulty of modulating the energy levels of fullerene derivatives.Thus,design of new non-fullerene small molecule acceptor(NFSMA)is very significant to match with these mature polymer donors and improve the V_(oc)and power conversion efficiency(PCE).Here,a new benzotriazole(BTA)-based NFSMA,BTA7 was synthesized by adopting A_2@A_1ADAA_1@A_2type molecular backbone.By using a strong electron-accepting unit of malononitrile(M)as terminal segment A_2,BTA7 demonstrates strong crystallinity,red-shifted absorption spectrum and down-shifted lowest unoccupied molecular orbital(LUMO)energy levels in comparison with BTA_1and BTA_2.Organic solar cells(OSCs)based on PTB7-Th:BTA7 realized a high V_(oc)of 1.05 V with a moderate PCE of 4.60%.The energy loss(E_(loss)=E_gàe V_(oc))of 0.53 e V is lower than the experiential minimum value of0.6 e V,which indicates PTB7-Th still has large potential to improve the V_(oc)and photovoltaic performance after the development of novel electron acceptors.展开更多
基金supported by the National Natural Science Foundation of China (51773029, 51533005 and 51373190)the National Key Research & Development Program of China (2016YFB0401002)+1 种基金Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the 111 Project and Qing Lan Project, China
基金supported by the National Key Research and Development Program of China (2017YFA0206600)the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (QYZDB-SSW-SLH033)+1 种基金the National Natural Science Foundation of China (51673048, 51473040 and 21602040)the Natural Science Foundation of Beijing (2162045)
文摘The open-circuit voltage(V_(oc))of classical photovoltaic polymers,such as P3HT and PTB7-Th,are always restricted when combining with fullerene derivatives,due to the difficulty of modulating the energy levels of fullerene derivatives.Thus,design of new non-fullerene small molecule acceptor(NFSMA)is very significant to match with these mature polymer donors and improve the V_(oc)and power conversion efficiency(PCE).Here,a new benzotriazole(BTA)-based NFSMA,BTA7 was synthesized by adopting A_2@A_1ADAA_1@A_2type molecular backbone.By using a strong electron-accepting unit of malononitrile(M)as terminal segment A_2,BTA7 demonstrates strong crystallinity,red-shifted absorption spectrum and down-shifted lowest unoccupied molecular orbital(LUMO)energy levels in comparison with BTA_1and BTA_2.Organic solar cells(OSCs)based on PTB7-Th:BTA7 realized a high V_(oc)of 1.05 V with a moderate PCE of 4.60%.The energy loss(E_(loss)=E_gàe V_(oc))of 0.53 e V is lower than the experiential minimum value of0.6 e V,which indicates PTB7-Th still has large potential to improve the V_(oc)and photovoltaic performance after the development of novel electron acceptors.
