The mechanism of how the solvent type influences photovoltaic performance and thermal stability of non-fullerene organic solar cells remains unexplored. In this article, the well-known PTB7-Th was selected as a donor, while F8IC was used as an acceptor. The PTB7-Th:F8IC processed from chloroform (CF) exhibited a superiorly higher power conversion efficiency (PCE) of 10.5%, in contrast to the specimen processed from chlorobenzene (CB) of 6.8%. In addition, upon thermal annealing at 160 °C for 120 min, the device processed from CF was more stable than that processed from CB. The incorporation of perylene diimide derivative TBDPDI-C11, serving as the third additive, could also obviously improve the PCE value and thermal stability of PTB7-Th:F8IC processed from CB. According to ultraviolet spectroscopy, atomic force microscopy, transmission electron microscopy, and grazing incidence wide-angle X-ray scattering analyses, the enhanced photovoltaic performance and thermal stability are mainly attributed to formation of PTB7-Th nanofibers and appropriate aggregation of F8IC. The interaction free energy calculated using water and diiodomethane contact angles reveals that PTB7-Th well disperses in CB and tends to aggregate in CF, while F8IC aggregates strongly in CB. The preaggregation matching of the donor and acceptor in solution is essential for the optimization of morphology, efficiency, and thermal stability. The findings in this article could provide useful guidelines to fabricate efficient and thermally stable organic solar cells simply by analyzing the surface energy of components processed from different solvents.

The mechanism of how the preaggregation of components induced by the solvent type affects the crystallization and miscibility of Y6-based blends remains to be explored. In this article, PDCBT-2F and N2200 serving as polymer additives were incorporated into the high-performance PM6:Y6 system to investigate morphological evolution as well as photovoltaic performance. It is found that both PDCBT-2F and N2200 could enhance the power conversion efficiency (PCE) of PM6:Y6 solar cells when processed with chloroform (CF). Unfortunately, the PCE value sharply reduced when processed with chlorobenzene (CB), which further decreased upon the incorporation of PDCBT-2F. In contrast, N2200 could still improve the performance of solar cells due to the formation of interconnected fibrils, although Y6 formed large-scale aggregates as observed using a transmission electron microscope (TEM). According to the UV spectra in solution and surface energy analysis, the components show close free energy in CF, indicating preaggregation matching of components. In contrast, the free energies of Y6 and PDCBT-2F in CB are different from those of PM6 and N2200, and the mismatching of preaggregation of the components contributes to the poor performance of solar cells. Based on the differential scanning calorimetry (DSC) analysis, the multiple melting peaks of Y6 corresponding to the face-on and edge-on crystals have been distinguished. The Flory−Huggins interaction parameters in Y6-based blends were highly influenced by the solvent type. N2200 shows higher miscibility with Y6 than PDCBT-2F, and N2200 induces the crystallization of Y6. The variation of miscibility induced by the preaggregation in different solvents could provide theoretical guidelines to optimize or control the morphology of the active layer as well as the resulting performance of organic solar cells.

Stability is still the main barrier to the commercial application of organic solar cells (OSCs), although the maximal power conversion efficiency (PCE) value has exceeded 19%. The encapsulation technique is an effective and vital way to guarantee the long-term stabilities of OSCs, but it can only avoid the penetration of water and oxygen from the environment. Herein, we introduced a structure that provides dual interface protection by using commercially available and chemically stable polyvinylidene fluoride (PVDF) as the cathode interface protection layer working as the cathode interlayer (CIL) and poly­(styrene-comethyl-methacrylate) (PS-r-PMMA) as the anode interface protection layer between the poly­(3,4-ethylenedioxythiophene)/poly­(styrene sulfonate) (PEDOT:PSS) and the active layer. With this structure, both the migration of impurities caused by degradation of the interfacial layer and the infiltration of oxygen and water in the air can be prevented. PVDF can effectively provide optimal electron transfer by improving the surface potential of active layers and lowering the work function of the Al electrode. PS-r-PMMA can improve the hydrophobicity of PEDOT:PSS and induce optimized phase separation, facilitating charge transfer. After storage in an air environment with a humidity of approximately 60% for 3600 h, the device based on the PM6:IT-4F blend film with dual interface protection showed a decrease in its PCE value from 13.43 to 10.90%, retaining 81.2% of its original PCE value, in contrast to the sharp decrease in the PCE value from 13.66 to 0.74% of the device without dual interface protection. The dual interface protection design could also be useful in the high-performance PM6:Y6 system, which shows a champion PCE of 15.39% and shows potential for the effective fabrication of stable OSCs in the future.

HELQ plays a key role in DNA damage response and cell-cycle checkpoint regulation. It has been implicated in ovarian and pituitary tumors and may play a role in germ cell maintenance. This study investigated the role of HELQ in lung cancer. The expression of HELQ in patients with non-small-cell lung cancer (NSCLC) was downregulated compared with normal human lungs. Clinical prognostic analysis of Kaplan-Meier plots revealed that patients with NSCLC with low HELQ levels had a reduced overall survival. Further, we found that HELQ depletion enhanced lung cancer cell malignancy. Furthermore, overexpression of HELQ in lung cancer cells reduced cell migration in vitro, while DNA damage repair was inhibited. Both in vitro C Cell ell B Biology iology I International nternational ZHONG ET AL.