Kim, Ji-yeong Park, Sungmin Lee, Seungjin Ahn, Hyungju Joe, Sung-yoon Kim, Bumjoon J. Son, Hae Jung 2024-01-19T21:32:32Z 2024-01-19T21:32:32Z 2021-09-05 2018-10-25 1614-6832 https://pubs.kist.re.kr/handle/201004/120770 Donor-acceptor random copolymers incorporating 1,3-bis(thiophen-2-yl)-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c]dithiophene-4,8-dione (BDD) and 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b]dithiophene (BDT-Th) are developed. Nonfullerene solar cells introducing the random copolymer PBDB-T73 (BDT-Th:BDD=7:3) and 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 are found to exhibit efficiency of 11.14%, which is superior to that of the PBDB-T alternating copolymer (10.02%). The PBDB-T73 device exhibits high performance due to low bimolecular charge recombination and good charge transport balance even though none of the treatments that are usually necessary for improving crystalline properties of active layers are performed; in contrast, the PBDB-T device requires thermal annealing in order to enhance the polymer's crystallinity and obtain improved fill factor and J(sc) values. It is demonstrated that efficient charge transport occurs in the PBDB-T73 blend despite relatively low crystallinity of the polymer. The percolating network structure of the large mixed phase in the PBDB-T73 blend has an important role in its efficient charge transport. Moreover, due to the low-temperature processability of PBDB-T73, flexible PBDB-T73 solar cell devices prepared on polyethylene terephthalate (PET) substrates exhibit high photovoltaic performance, 10.02%, whereas the efficiency of PBDB-T-based flexible devices (7.2%) is significantly lower due to damage to the active layer on indium tin oxide (ITO)/PET that results from thermal annealing. English WILEY-V C H VERLAG GMBH BANDGAP CONJUGATED POLYMER NON-FULLERENE ACCEPTORS ELECTRON-ACCEPTORS MORPHOLOGY CONTROL SIDE-CHAINS ORGANIC PHOTOVOLTAICS MOLECULAR-WEIGHT DONOR POLYMER EFFICIENCY ENABLES Low-Temperature Processable High-Performance D-A-Type Random Copolymers for Nonfullerene Polymer Solar Cells and Application to Flexible Devices Article 10.1002/aenm.201801601 1 ADVANCED ENERGY MATERIALS, v.8, no.30 ADVANCED ENERGY MATERIALS 8 30 scie scopus 000448257300008 2-s2.0-85053061906 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article BANDGAP CONJUGATED POLYMER NON-FULLERENE ACCEPTORS ELECTRON-ACCEPTORS MORPHOLOGY CONTROL SIDE-CHAINS ORGANIC PHOTOVOLTAICS MOLECULAR-WEIGHT DONOR POLYMER EFFICIENCY ENABLES morphology nonfullerene acceptors polymer solar cells power conversion efficiency random copolymers