Chul Baik

Molecular engineering of organic sensitizers containing p-phenylene vinylene unit for dye-sensitized solar cells.

Three organic sensitizers containing bis-dimethylfluorenyl amino donor and a cyanoacrylic acid acceptor bridged by p-phenylene vinylene unit were synthesized. The power conversion efficiency was quite sensitive to the length of bridged phenylene vinylene groups. A nanocrystalline TiO2 dye-sensitized solar cell was fabricated using three sensitizers. The maximum power conversion efficiency of JK-59 reached 7.02%.

High efficient donor–acceptor ruthenium complex for dye-sensitized solar cell applications

A highly efficient heteroleptic ruthenium (II) complex cis-di(thiocyanato)(4,4′-dicarboxylic acid-2,2′-bipyridine)(4,4′-di-(2-(4-ditolylamine phenyl)ethenyl)-2,2′-bipyridine) ruthenium (II) (IJ-1) was synthesized and characterized, which when anchored on nanocrystalline TiO2 films exhibited high power conversion efficiency, 10.3%, and incident photon to electron conversion efficiency, 87%.

Molecular Design of Near-IR Harvesting Unsymmetrical Squaraine Dyes

The functionalized unsymmetrical benzothiazole squaraine organic sensitizers 5-carboxy-2-({3-[(3-hexylbenzothiazol-2(3H)-ylidene)methyl]-2-hydroxy-4-oxo-2-cyclobuten-1-ylidene}methyl)-1-hexyl-3,3-dimethyl-3H-indolium (hereafter named as SK-11) and 5-carboxy-2-({3-[(3-hexyl-5-methoxybenzothiazol-2(3H)-ylidene)methyl]-2-hydroxy-4-oxo-2-cyclobuten-1-ylidene}methyl)-1-hexyl-3,3-dimethyl-3H-indolium (coded as SK-12) are designed and developed to observe an intense and wider absorption band in the red/NIR wavelength region. DFT/TDDFT calculations have been performed on the two unsymmetrical squaraine sensitizers to gain insight into their electronic and optical properties. The utility of these dyes in solid state dye sensitized solar cells (SS-DSSCs) is demonstrated.

Molecular engineering of hybrid sensitizers incorporating an organic antenna into ruthenium complex and their application in solar cells

Two novel hybrid sensitizers incorporating an organic antenna into a ruthenium complex have been synthesized and applied successfully in nanocrystalline TiO2 based solar cells, which yielded solar to electricity conversion efficiencies of 8.20–9.16% under AM 1.5 sunlight.