| 초록 |
In this work, the impact of temperature-dependent aggregation (TDA) behaviors in benzodithiophene (BDT)-based polymer donors (PDs) on the electrical, morphlogical and photovoltaic performances of all-polymer solar cells (all-PSCs) is investgated. Two PDs, PBDB-T and PBDB-Bz, with thienyl or benzylthienyl side chains and identical backbones are prepared. In contrast to PBDB-T, PBDB-Bz with bulkier side chains exhibits strong aggregation behavior in solution independent of temperatures between 20 and 100 ℃. Notably, PBDB-Bz-based all-PSCs show a power conversion efficiency (PCE) of over 9% without any solvent additives (SA) or thermal annealing (TA), whereas these treatments are inevitable in optimizing the PCE of PBDB-T-based all-PSCs. Furthermore, high PCEs for the PBDB-Bz-based devices are maintained irrespective of their processing temperatures (Tproc). However, the PCEs of PBDB-T-based devices are strongly dependent on their SA, TA and Tproc conditions. Thus, the development of PDs with temperature-insensitive, strong aggregation behavior is crucial in producing reproducible, Tproc-tolerant and additive-free high-performance all-PSC devices. |
