Effects of heteroatom substitution in conjugated heterocyclic compounds on photovoltaic performance: from sulfur to tellurium.
We report a general strategy for fine-tuning the bandgap of donor-acceptor-donor based organic molecules by modulating the electron-donating ability of the donor moiety by changing the benzochalcogenophene donor groups from benzothiophenes to benzoselenophenes to benzotellurophenes. These molecules show red-shifts in absorption and external quantum efficiency maxima from sulfur to selenium to tellurium. In bulk heterojunction solar cell devices, the benzoselenophene derivative shows a power conversion efficiency as high as 5.8% with PC61BM as the electron acceptor.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA.
Y S
YS
Park
T S
TS
Kale
C-Y
CY
Nam
D
D
Choi
R B
RB
Grubbs
D011211:Electric Power Supplies; D006571:Heterocyclic Compounds / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes; D013455:Sulfur / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*
D006571:Heterocyclic Compounds; D013455:Sulfur; D013691:Tellurium