Abstract
This work was dedicated to improve N749 . In part I, sensitizers 2.1 - 2.3 which bear 4,4’,4’’-tricarboxy-2,2’:6’,2’’-terpyridine (tctpy), a functional pyridinyl pyrazolate,and a thiocyanate ligand. were successfully synthesized. Alkyl group was tethered to the para-position of pyridyl group to avoid dye aggregation. These new sensitizers exhibited significantly higher molar extinction coefficients at 400 550 nm versus N749, leading better light-harvesting capability across visible and near infrared region (NIR), giving a superior performance to DSC cells. Sensitizer 2.1 showed an overall conversion efficiency = 9.68%. In part II, two sensitizers which bear 4,4’,4’’-tricarboxy-2,2’:6’,2’’-terpyridine (tctpy) and tridentate ancillary ligand, Ru(II) complex 2.4 and 2.5 were successfully produced. The tridentate ancillary ligand was used to substitute three thiocyanate ligands originally attached onto N749, which not only avoided the usage of unstable thiocyanate but also increased the product yield. Modifying fluoroalkyl substituents onto the pyrazolyl framework and tethering t-butyl group to the para-position of pyridyl group were to prerent the charge from recombination. In part III, two sensitizers which bear 4''-phosphoxy -4,4'-dicarboxy -2,2':6',2''-terpyridine (H4pdctpy) and tridentate ancillary ligand, Ru(II) complex 2.6 and 2.7 were successfully synthesized. The tridentate ancillary ligand was used to substitute three thiocyanate ligands. The lifespan of solar cells fabricated with sensitizer 2.7 exhibited a stable performance on efficiency over 1500 hours.