TY - JOUR
T1 - High efficiency and stability small molecule solar cells developed by bulk microstructure fine-tuning
AU - Min, Jie
AU - Jiao, Xuechen
AU - Sgobba, Vito
AU - Kan, Bin
AU - Heumüller, Thomas
AU - Rechberger, Stefanie
AU - Spiecker, Erdmann
AU - Guldi, Dirk M.
AU - Wan, Xiangjian
AU - Chen, Yongsheng
AU - Ade, Harald
AU - Brabec, Christoph J.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Morphological control over the bulk heterojunction (BHJ) microstructure of a high-efficiency small molecule photovoltaic system composed of a quinquethiophene based molecule (DRCN5T) as electron donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM) as electron acceptor is demonstrated using three different post-processing strategies, including thermal annealing (TA), solvent vapor annealing (SVA), and two-step annealing (TA-SVA) treatments. We systematically analyze the processing condition-microstructure-device property relationships, explore the corresponding morphology evolution and their effects on carrier transport and recombination dynamics in BHJs as well as understand the nature of phase-separation process resulting in light-induced degradation mechanisms. Within the investigated results, the causative relations between annealing sequence, photovoltaic parameters, morphology evolution and charge carrier dynamics are for the first time delineated. In addition, the observed trade-offs in device efficiency and stability with respect to the well-defined morphologies are highlighted. The in-depth picture of the bulk microstructure formation and its kinetic evolution as a function of the specific post-processing approaches is a valuable asset for the design of new photovoltaic materials and thin film nanoscale architectures that are more efficient and better aid future commercialization efforts.
AB - Morphological control over the bulk heterojunction (BHJ) microstructure of a high-efficiency small molecule photovoltaic system composed of a quinquethiophene based molecule (DRCN5T) as electron donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM) as electron acceptor is demonstrated using three different post-processing strategies, including thermal annealing (TA), solvent vapor annealing (SVA), and two-step annealing (TA-SVA) treatments. We systematically analyze the processing condition-microstructure-device property relationships, explore the corresponding morphology evolution and their effects on carrier transport and recombination dynamics in BHJs as well as understand the nature of phase-separation process resulting in light-induced degradation mechanisms. Within the investigated results, the causative relations between annealing sequence, photovoltaic parameters, morphology evolution and charge carrier dynamics are for the first time delineated. In addition, the observed trade-offs in device efficiency and stability with respect to the well-defined morphologies are highlighted. The in-depth picture of the bulk microstructure formation and its kinetic evolution as a function of the specific post-processing approaches is a valuable asset for the design of new photovoltaic materials and thin film nanoscale architectures that are more efficient and better aid future commercialization efforts.
KW - Annealing sequence
KW - Blend microstructure
KW - Charge carrier dynamics
KW - Degradation mechanisms
KW - Morphological control
KW - Phase-separation
UR - http://www.scopus.com/inward/record.url?scp=84984846059&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2016.08.047
DO - 10.1016/j.nanoen.2016.08.047
M3 - Article
AN - SCOPUS:84984846059
SN - 2211-2855
VL - 28
SP - 241
EP - 249
JO - Nano Energy
JF - Nano Energy
ER -