Importantly, three batches of PNTB6-Cl with varying molecular weights (Mn: 45.27-91.53 KDa) exhibited PCE deviation smaller than 4 %. It was further revealed that the chloroform processing dissolved the PNTB-Cl in both amorphous and crystalline regions, however, it only partially washed away amorphous PNTB6-Cl which bring forth the advantage of reducing the traps in LBL films that benefits the FF value, facilitating electron acceptor penetration. This study suggests the importance of controlling solubility properties of polymer donors toward high-performance LBL-OSCs. The use of different additives to control the donor and acceptor layers separately is a promising approach to achieve high efficiency of LbL-OSCs. Zhang et al. [67]prepared PNTB6-Cl:Y6-based LbL-OSCs by adding DPE and DFB solvent additives into PNTB6-Cl chlorobenzene solution and Y6 chloroform solution separately. It improves the photogenerated exciton distribution, charge transport and collection, resulting in PCE of 17.53 % that is much higher than 16.38 % for controlled devices. Using the same processing approach, they fabricated PNTB6-Cl: BTP-4F-12-based LbL-OSCs and achieved a PCE of 17.81 % by using DPE and DIO to optimize donor and acceptor layers separately.[68] Shaoet al. [71] reported a self-powered organic photodetector (OPD) based on PNTB6-Cl:Y6 blend active film. The PNTB6-Cl:Y6 blend film exhibited a remarkable intrinsic stretchability up to 100 % strain. The OPD not only exhibited impressive weak-light detection ability, but also had a high anisotropic response rate of 1.42 under parallel and transversely polarized light irradiation.