title: A strategic buffer layer of polythiophene enhances the efficiency of bulk heterojunction solar cells.
abstract: We have developed polymer solar cells featuring a buffer layer of polythiophene (PT) sandwiched between the active layer and the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer. We attribute the improvement in power conversion efficiency of these polymer solar cells, relative to that of those based on poly(3-hexylthiophene):[6,6]-phenyl-C(61)-butyric acid methyl ester (P3HT:PCBM), to a reduction in the degree of carrier recombination at the junction interface. Because the conductivity and the energy level of PT can be tuned simply by applying a bias to it in an electrolytic solution, we also investigated the effect of the energy level on the devices' performances. The power conversion efficiency of a solar cell containing a PT buffer layer reached 4.18% under AM 1.5 G irradiation (100 mW/cm(2)).
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Wei
authors.forename: Jen-Hsien
authors.initials: JH
authors.lastname: Huang
authors.forename: Kuo-Chuan
authors.initials: KC
authors.lastname: Ho
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Chu
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry* / Q000528:radiation effects*; D012993:Solar Energy; D013876:Thiophenes / Q000737:chemistry* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D011108:Polymers; D013876:Thiophenes; C066730:polythiophene