Recent advances in polymer solar cell (PSC) performance have resulted from compressing the bandgap to enhance the short-circuit current while lowering the highest occupied molecular orbital to increase the open-circuit voltage. Nevertheless, PSC power conversion efficiencies are still constrained by low fill factors, typically below 70%. Here, we report PSCs with exceptionally high fill factors...

A new wide band gap polymer PIDT-AQx with indacenodithiophene (IDT) as the electron-rich unit and acenaphthoquinoxaline (AQx) as the electron-deficient unit has been designed and synthesized. The optical band gap of PIDT-AQx was 1.81 eV with a HOMO energy level of −5.13 eV. Polymer solar cells with the blend of PIDT-AQx/PC71BM as the active layer achieved a power conversion efficiency (PCE) of ...

A new conjugated donor-acceptor (D-A) polymer pDSBT2-BT containing bi(disilano-bisthiophene) and benzothiadiazole as donor and acceptor units, respectively, was prepared. The polymer showed a broad UV-vis absorption band at λmax = 599 nm in chlorobenzene. The absorption band was shifted to λmax = 629 nm when the polymer was measured as a film, indicating enhanced interchain interactions of the ...

A critical issue in polymer-based solar cells (PSCs) is to improve the power conversion efficiency (PCE) as well as the stability. Here, we describe the development of new semiconducting polymers consisting of thiophene, thiazolothiazole and naphthobisthiadiazole in the polymer backbone. The polymers had good solubility and thus solution-processability, appropriate electronic structure with nar...

Two novel triads based on a diketopyrrolopyrrole (DPP) central core and two 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) units attached by thiophene rings have been synthesised having high molar extinction coefficients. These triads were characterised and used as donor materials in small molecule, solution processable organic solar cells. Both triads were blended with PC71BM as an accept...

Charge separation and extraction dynamics were investigated in high-performance bulk heterojunction solar cells made from the polymer PTB7 and the soluble fullerene PC71BM on a broad time scale from subpicosecond to microseconds using ultrafast optical probing of carrier drift and the integral-mode photocurrent measurements. We show that the short circuit current is determined by the separation...