Tuning the absorption, charge transport properties, and solar cell efficiency with the number of thienyl rings in platinum-containing poly(aryleneethynylene)s.
The synthesis, characterization, and photophysics of a series of solution-processable and strongly visible-light absorbing platinum(II) polyynes containing bithiazole-oligo(thienyl) rings were presented. Tuning the polymer solar cell efficiency, as well as optical and charge transport properties, in soluble, low-band gap PtII-based conjugated poly(heteroaryleneethynylene)s using the number of oligothienyl rings is described. These materials are highly soluble in polar organic solvents due to the presence of solubilizing bithiazole moieties and show strong absorptions in the solar spectra, rendering them excellent candidates for bulk heterojunction polymer solar cells. Their photovoltaic responses and power conversion efficiencies (PCEs) depend to a large extent on the number of thienyl rings along the main chain, and some of them can be used to fabricate highly efficient solar cells with PCEs of up to 2.7% and a peak external quantum efficiency to 83% under AM1.5 simulated solar illumination, which is comparable to that of poly(3-hexylthiophene)-based devices fabricated without additional processing (annealing or TiO(x) layer). The influence of the number of thienyl rings and the metal group on the performance parameters and optimization of solar cell efficiency was evaluated and discussed in detail. At the same blend ratio of 1:4, the light-harvesting ability and PCE increase sharply as the thienyl chain length increases. The present work provides an attractive approach to developing conjugated metallopolymers offering broad solar absorptions and tunable solar cell efficiency and demonstrates the potential of metalated conjugated polymers for efficient power generation.
Wong
Wai-Yeung
WY
Department of Chemistry, Centre for Advanced Luminescence Materials, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong, PR China. rwywong@hkbu.edu.hk
Wang
Xing-Zhu
XZ
He
Ze
Z
Chan
Kwok-Kwan
KK
Djurisić
Aleksandra B
AB
Cheung
Kai-Yin
KY
Yip
Cho-Tung
CT
Ng
Alan Man-Ching
AM
Xi
Yan Yan
YY
Mak
Chris S K
CS
Chan
Wai-Kin
WK