Synthesis of a novel heptamethine–cyanine dye for use in near-infrared active dye-sensitized solar cells with porous zinc oxide prepared at low temperature

Abstract

A novel near-infrared-absorbing heptamethine-cyanine dye (KFH-3) that contains four n-butyl groups was synthesized for use in highly efficient dye-sensitized solar cells with porous zinc oxide (ZnO) prepared at low temperature, and resulted in remarkable performance characteristics, such as a conversion efficiency of 1.23% (AM 1.5) with an incident photon-to-current conversion efficiency (800 nm) of 33%, a short-circuit photocurrent density of 3.34 mA, an open-circuit photovoltage of 0.49, and a fill factor of 0.76, using almost solely the near-infrared region of sunlight.

Polymethine Dyes in Hybrid Photovoltaics: Structure–Properties Relationships

“…Another way to reduce aggregation has been proposed by Funabiki et al [S127,128] 123. Comparing two heptamethines, they reported higher J SC for the cyanine synthesized starting from 2‐methyl‐3,3‐dibutylindolenine with respect to 2,3,3‐trimethylindolenine (Figure 24).…”

Rapid, low-temperature processing of dye-sensitized solar cells

“…Broadly, these dye families can be described as coumarins (Hara et al , 2003;, indolines (Horiuchi et al , 2003;Ito et al , 2006) and triarylamines (Hwang et al , 2007;Gang, 2009;Zhang et al , 2009;Im et al , 2010). However, there is increasing interest in dyes which can absorb photons at longer wavelengths (i.e., into the NIR region) such as phthalocyanines (Yum et al , 2008;Bessho et al , 2010;Mori et al , 2010;Garcia-Iglesias et al , 2011), squaraines Geiger et al , 2009;Bagnis et al , 2010;Choi et al , 2010;Shi et al , 2011) and cyanines (Ono et al , 2009;Funabiki et al , 2011). Closely linked to research into dyes which absorb in different parts of the solar spectrum is the concept of dyeing photo-electrodes with more than one dye.…”

Recent Progress in ZnO-Based Nanostructured Ceramics in Solar Cell Applications

“…Acriflavine or 1,6diamino-10-methylacridinium chloride dyes also showed higher interfacial electron recombination resistance compared to ruthenium-based dyes. 34 Other dyes which had absorption wavelengths nearer the infra-red region including heptamethine-cyanine dyes (600-800 nm), 58 and "evans blue" dye. 73 There has also been work in the use of natural dyes with ZnO nanostructured solar cells.…”