TY  - JOUR
AU  - Huang, Tzu-Yen
AU  - Le Brun, Anton P.
AU  - Sochor, Benedikt
AU  - Wu, Chun-Ming
AU  - Bulut, Yusuf
AU  - Müller-Buschbaum, Peter
AU  - Roth, Stephan V.
AU  - Yang, Yanzhao
TI  - Nanometer-Thick ITIC Bulk Heterojunction Films as Non-Fullerene Acceptors in Organic Solar Cells
JO  - ACS applied nano materials
VL  - 7
IS  - 15
SN  - 2574-0970
CY  - Washington, DC
PB  - ACS Publications
M1  - PUBDB-2025-00176
SP  - 17588-17595
PY  - 2024
N1  - Waiting for fulltext 
AB  - The nanomorphology of bulk heterojunctions (BHJs) plays a critical role in determining the performance of non-fullerene organic solar cells (OSCs). Thermal annealing is commonly used to reorganize the donor and acceptor phases within the BHJs. In this study, we investigate the vertical morphology of BHJ blend films incorporating the poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2′;5′,2″;5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) polymer as the donor 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 (ITIC) as the acceptor. Neutron reflectivity patterns and scattering length density profiles reveal that the surface of the BHJ films became diffuse when the annealing temperature was above 150 °C. We further find that mitigated agglomeration of PffBT4T-2OD side chains exhibits minimal impact on morphology post-annealing. Instead, ITIC molecules trigger aggregations, accompanied by interface diffusion and increased film roughness. X-ray scattering confirms a 5-fold increase in aggregated ITIC nanodomains after annealing. Our findings highlight that unstable ITIC phases dominate the BHJ morphology of thin films, leading to the thermal instability of OSCs. This study enhances our understanding of the BHJ morphology and offers insights into improving the performance of energy conversion devices.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001277938500001
DO  - DOI:10.1021/acsanm.4c02865
UR  - https://bib-pubdb1.desy.de/record/622090
ER  -