Phenoxazine-based panchromatic organic sensitizers for dye-sensitized solar cells

A series of metal-free organic dyes LJJ101-LJJ103 composed of phenoxazine unit and indolinum carboxyl acid derivative have been synthesized for dye-sensitized solar cells. A systematic investigation has been conducted for the photology and electrochemistry properties of dyes LJJ101-LJJ103. Panchromatic spectra responses for all the three dyes have been obtained and extended to about 800 nm in near-infrared region. Compared to LJJ101, the introduction of thiophene and squaraine unit causes a red-shift absorption response for LJJ102 and LJJ103, respectively. When applied in dye-sensitized solar cells under AM 1.5 illumination, the device sensitized by LJJ103 yields the best conversion efficiency of 5.1% with a short-circuit photocurrent density of 13.7 mA/cm(2), an open-circuit photovoltage of 502 mV and a fill factor of 74.0%. (C) 2015 Elsevier Ltd. All rights reserved.