Enhanced Performance of Organic Solar Cells with Increased End Group Dipole Moment in Indacenodithieno[3,2‐b]thiophene‐Based Molecules

Publisher: John Wiley & Sons Inc

E-ISSN: 1616-3028|25|30|4889-4897

ISSN: 1616-301x

Source: ADVANCED FUNCTIONAL MATERIALS, Vol.25, Iss.30, 2015-08, pp. : 4889-4897

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Four new molecular donors are reported using a D1‐A‐D2‐A‐D1 structure, where D1 is an oligiothiophene, A is a benzothiadiazole, and D2 is indacenodithieno[3,2‐b]thiophene. The resulting materials provide efficiencies as high as 6.5% in organic solar cells, without the use of solvent additives or thermal/solvent annealing. A strong correlation between the end group (D1‐A) dipole moment and the fill factor (FF), mobility, and loss in the open‐circuit voltage (VOC) is observed. Indacenodithieno[3,2‐b]thiophene‐fluorobenzothiadiazole‐terthiophene (IDTT‐FBT‐3T) possesses the largest end group dipole moment, and in turn, has the highest mobility, FF, and power conversion efficiency in devices. It also has a similarly high VOC (0.95 V) to the other materials (0.93–0.99 V), despite possessing a much higher highest occupied molecular orbital (HOMO) energy level.

Related content