title: Near infrared thieno[3,4-b]pyrazine sensitizers for efficient quasi-solid-state dye-sensitized solar cells.
abstract: Three near infrared (NIR) metal-free organic sensitizers (FNE32, FNE34, FNE36) based on the thieno[3,4-b]pyrazine derivative have been designed and synthesized for application in quasi-solid-state dye-sensitized solar cells (DSSCs). These organic dyes demonstrate maximum absorption bands at 596-625 nm due to the presence of the thieno[3,4-b]pyrazine derivative, which facilitates the intramolecular electron transfer from the donor to the acceptor. Quasi-solid-state DSSCs based on FNE34 display efficient photoelectric conversion over the whole visible range extending into the NIR region up to 900 nm with maximum incident monochromatic photon-to-electron conversion efficiency (IPCE) of 77%, yielding a short-circuit photocurrent density of 16.24 mA cm(-2) and a power conversion efficiency of 5.30%. To the best of our knowledge, this is the highest efficiency for quasi-solid-state DSSCs based on an organic NIR dye. When exposed to one-sun illumination for 1000 h, the quasi-solid-state DSSC based on FNE34 exhibits good long-term stability with almost constant power conversion efficiency.
authors.affiliation: Department of Chemistry & Laboratory of Advanced Materials, Fudan University, 2205 Songhu Road, Shanghai 200438, P. R. China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Lu
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Quanyou
authors.initials: Q
authors.lastname: Feng
authors.forename: Zhong-Sheng
authors.initials: ZS
authors.lastname: Wang