Jheng-Ying Li

Highly Efficient Light-Harvesting Ruthenium Sensitizer for Thin-Film Dye-Sensitized Solar Cells

A high molar extinction coefficient heteroleptic ruthenium complex, incorporating an electron-rich hexylthio-terminal chain, has been synthesized and demonstrated as an efficient sensitizer for dye-sensitized solar cells. With this new sensitizer excellent power conversion efficiency is 11.5% and 4.7% obtained under an irradiation of full sunlight (air mass 1.5 global) in combination with a volatility electrolyte and solid state hole transporting material, respectively. The devices with low volatility electrolyte showed good stability under visible-light soaking at 60 degrees C during 1000 h of accelerated tests.

Unsymmetrical squaraines incorporating the thiophene unit for panchromatic dye-sensitized solar cells.

Two unsymmetrical squaraines, where the electron-rich 3,4-ethylenedioxythiophene or bithiophene conjugated fragment was used to link unconventionally the squaraine core and the hexyloxyphenyl amino group, were applied for DSCs. The corresponding photovoltaic devices exhibit an attractively panchromatic response and also convert a portion of the near-infrared photons into electricity.

Heteroleptic ruthenium antenna-dye for high-voltage dye-sensitized solar cells

A new ruthenium photosensitizer, coded CYC-B7, incorporating a bithienyl-carbazole antenna ligand was designed and prepared for improving the open-circuit voltage (Voc) of a dye-sensitized solar cell (DSC) device. This new sensitizer displays the low energy MLCT transition band centered at 551 nm with a high molar absorption coefficient of 2.19 × 104 M−1 cm−1. In addition, a simple approach to reduce the aggregation of bulky ruthenium dyes assembled onto the surface of TiO2 film is demonstrated. The cell based on this new heteroleptic ruthenium dye provides a high Voc of 788 mV and an overall conversion efficiency (η) of 8.96%. The functionality of carbazole in CYC-B7 resulting in the increases of the Voc value of the corresponding device is verified by comparing with the performance of the DSC sensitized with a structurally similar dye without carbazole.

Unsymmetrical squaraines incorporating quinoline for near infrared responsive dye-sensitized solar cells.

Two new unsymmetrical squaraines (WCH-SQ10 and WCH-SQ11), wherein the electron-rich 3,4-ethylenedioxy-thiophene conjugated fragment was linked unconventionally to the squaraine core and triphenyl amine donor, and carboxylic acid substituted quinoline was used as an acceptor, were prepared. WCH-SQ10 and WCH-SQ11 dyes in ethanol have the λ(max) of 686 and 673 nm, respectively. The corresponding photovoltaic devices exhibit an attractively panchromatic response over 1000 nm, suggesting that quinoline benefits the low energetic electron injection.