The approach of a hydrophilic group grafted buffer layer (HGGBL) was investigated for perovskite growth to realize highly efficient inverted planar perovskite solar cells with superior reproducibility, negligible hysteresis and improved stability.

Solution processing of semiconductors is highly promising for the high-throughput production of cost-effective electronics and optoelectronics. Although hybrid perovskites have potential in various device applications, challenges remain in the development of high-quality materials with simultaneously improved processing reproducibility and scalability. Here, we report a liquid medium annealing (LMA) technology that creates a robust chemical environment and constant heating field to modulate crystal growth over the entire film. Our method produces films with high crystallinity, fewer defects, desired stoichiometry, and overall film homogeneity. The resulting perovskite solar cells (PSCs) yield a stabilized power output of 24.04% (certified 23.7%, 0.08 cm2) and maintain 95% of their initial power conversion efficiency (PCE) after 2000 hours of operation. In addition, the 1-cm2 PSCs exhibit a stabilized power output of 23.15% (certified PCE 22.3%) and keep 90% of their initial PCE after 1120 hours of operation, which illustrates their feasibility for scalable fabrication. LMA is less climate dependent and produces devices in-house with negligible performance variance year round. This method thus opens a new and effective avenue to improving the quality of perovskite films and photovoltaic devices in a scalable and reproducible manner.

Stretchable electronic materials have drawn strong interest due to their important applications in areas such as bioelectronics, wearable devices, and soft robotics. The stretchable electrode is an integral unit of stretchable systems. Intrinsically c o n d u c t i v e p o l y m e r s s u c h a s p o l y ( 3 , 4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) can have high mechanical flexibility and good biocompatibility. However, their electrical conductivity and mechanical stretchability should be greatly improved for its applications as the stretchable electrode. Here, we report highly conductive and highly stretchable PEDOT:PSS by incorporating biocompatible D-sorbitol. D-Sorbitol can serve as both the secondary dopant and plasticizer for PEDOT:PSS. It can not only significantly improve the conductivity but also the stretchability. D-Sorbitol-PEDOT:PSS (s-PEDOT:PSS) can have a conductivity of >1000 S/cm, and the conductivity could be maintained at a strain up to 60%. The resistance of s-PEDOT:PSS remains almost constant during repeated stretching−releasing cycles. The mechanism for the stretchability improvement by D-sorbitol is ascribed to the softening of PSSH chains. D-Sorbitol can position among the PSSH chains and thus destructs the hydrogen bonds among the PSSH chains. This makes the conformational change of the PSSH chains under stress become easy and thus increases the mechanical flexibility of PEDOT:PSS. This conductivity is the highest for biocompatible intrinsically conductive polymers with high stretchability.

A possible high efficiency working model of a monolayer PEDOT:PSS film and a brief fabrication process.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Microglia are the resident innate immune cells in the CNS; they play an important role in the processes of demyelination and remyelination in MS. Microglia can function as antigen-presenting cells and phagocytes. In the past, microglia were considered to be the same cell type as macrophages, and researchers have different opinions about the role of microglia in MS. This review focuses on the original classification of microglia and their role in the pathogenesis of MS. Moreover, we present a hypothetical model for the role of microglia in the pathogenesis of MS based on recent findings.