title: Increasing the open-circuit voltage in high-performance organic photovoltaic devices through conformational twisting of an indacenodithiophene-based conjugated polymer.
abstract: A fused ladder indacenodithiophene (IDT)-based donor-acceptor (D-A)-type alternating conjugated polymer, PIDTHT-BT, presenting n-hexylthiophene conjugated side chains is prepared. By extending the degree of intramolecular repulsion through the conjugated side chain moieties, an energy level for the highest occupied molecular orbital (HOMO) of -5.46 eV--a value approximately 0.27 eV lower than that of its counterpart PIDTDT-BT--is obtained, subsequently providing a fabricated solar cell with a high open-circuit voltage of approximately 0.947 V. The hole mobility (determined using the space charge-limited current model) in a blend film containing 20 wt% PIDTHT-BT) and 80 wt% [6,6]-phenyl-C71 butyric acid methyl ester (PC71 BM) is 2.2 × 10(-9) m(2) V(-1) s(-1), which is within the range of reasonable values for applications in organic photovoltaics. The power conversion efficiency is 4.5% under simulated solar illumination (AM 1.5G, 100 mW cm(-2)).
authors.affiliation: Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Road, Taishan, New Taipei City, 243, Taiwan.
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chen
authors.forename: Hsiang-Lin
authors.initials: HL
authors.lastname: Hsu
mesh_terms: D055664:Electrochemical Techniques; D009682:Magnetic Resonance Spectroscopy; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D011789:Quantum Theory; D012993:Solar Energy; D013056:Spectrophotometry, Ultraviolet; D013876:Thiophenes / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D011108:Polymers; D011137:Polystyrenes; D013876:Thiophenes; D017971:Tin Compounds; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); C109984:indium tin oxide
keywords: conjugated polymers; fullerenes; organic photovoltaics