title: High molar extinction coefficient organic sensitizers for efficient dye-sensitized solar cells.
abstract: We have designed and synthesized highly efficient organic sensitizers with a planar thienothiophene-vinylene-thienothiophene linker. Under standard global AM 1.5 solar conditions, the JK-113-sensitized cell gave a short circuit photocurrent density (J(sc)) of 17.61 mA cm(-2), an open-circuit voltage (V(oc)) of 0.71 V, and a fill factor (FF) of 72%, corresponding to an overall conversion efficiency (eta) of 9.1%. The incident monochromatic photo-to-current conversion efficiency (IPCE) of JK-113 exceeds 80% over the spectral region from 400 to 640 nm, reaching its maximum of 93% at 475 nm. The band tails off toward 770 nm, contributing to the broad spectral light harvesting. Solar-cell devices based on the sensitizer JK-113 in conjunction with a volatile electrolyte and a solvent-free ionic liquid electrolyte gave high conversion efficiencies of 9.1% and 7.9%, respectively. The JK-113-based solar cell fabricated using a solvent-free ionic liquid electrolyte showed excellent stability under light soaking at 60 degrees C for 1000 h.
authors.affiliation: Department of New Material Chemistry, Korea University, Jochiwon, Chungnam 339-700, Korea.
authors.forename: Hyunbong
authors.initials: H
authors.lastname: Choi
authors.forename: Ines
authors.initials: I
authors.lastname: Raabe
authors.forename: Duckhyun
authors.initials: D
authors.lastname: Kim
authors.forename: Francesca
authors.initials: F
authors.lastname: Teocoli
authors.forename: Chulwoo
authors.initials: C
authors.lastname: Kim
authors.forename: Kihyung
authors.initials: K
authors.lastname: Song
authors.forename: Jun-Ho
authors.initials: JH
authors.lastname: Yum
authors.forename: Jaejung
authors.initials: J
authors.lastname: Ko
authors.forename: Md K
authors.initials: MK
authors.lastname: Nazeeruddin
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel