A Polybenzo1,2‐b:4,5‐b′dithiophene Derivative with Deep HOMO Level and Its Application in High‐Performance Polymer Solar Cells

Sun catcher: The new benzo1,2-b:4,5-b′dithiophene-containing polymer PBDTTBT exhibits a power conversion efficiency of up to 5.66 %. The high open-circuit voltage (0.92 V) originates from the low HOMO level of the polymer and the high internal and external quantum efficiencies over a wide spectral range. PBDTTBT is a promising donor material for application in polymer solar cells.