During electrospinning, P(VDF‐TrFE), an electroactive polymer, acquires special electrical and mechanical properties. The development of a flexible, breathable pressure sensor based on P(VDF‐TrFE) nanofiber webs is reported that shows promise for use in human‐centered applications. The P(VDF‐TrFE) nanofiber webs are produced by electrospinning. The morphology and microstructure of webs are characterized using SEM, XRD, and ATR‐FTIR spectroscopy. Flexible pressure sensors are developed that are suitable for incorporation into fabrics and, using a custom‐made setup, is is demonstrated that they have a maximum sensitivity of 60.5 mV · N−1.

Surface passivation is increasingly one of the most prominent strategies to promote the efficiency and stability of perovskite solar cells (PSCs). However, most passivation molecules hinder carrier extraction due to poorly conductive aggregation between perovskite surface and carrier transportation layer. Herein, a novel molecule: p-phenyl dimethylammonium iodide (PDMAI) with ammonium group on both terminals is introduced, and its passivation effect is systematically investigated. It is found that PDMAI can mitigate defects at the surface and promote carrier extraction from perovskite to the hole transporting layer, leading to a lift of open-circuit voltage of 40 mV. Profiting from superior PDMAI passivation, the average efficiency of PSCs has been elevated from 19.69% to 20.99%. As demonstrated with density functional theory calculations, PDMAI probably tends to anchor onto the perovskite surface with both NH 3 I tails, and enhances the adhesion and contact to perovskite layer. The exposed hydrophobic aryl core protects perovskite against detrimental environmental factors. In addition, the alkyl component between aryl and ammonium groups is demonstrated to be essentially vital in triggering passivation function, which offers the guidance for the design of passivation molecules.

We have developed a highly sensitive flexible pressure sensor based on a piezopolymer and silver nanowires (AgNWs) composite. The composite nanofiber webs are made by electrospinning mixed solutions of poly(inylidene fluoride) (PVDF) and Ag NWs in a cosolvent mixture of dimethyl formamide and acetone. The diameter of the fibers ranges from 200 nm to 500 nm, as demonstrated by SEM images. FTIR and XRD results reveal that doping Ag NWs into PVDF greatly enhances the content of β phase in PVDF. This β phase increase can be attributed to interactions between the Ag NWs and the PVDF matrix, which forces the polymer chains to be embedded into the β phase crystalline. The sensitivity of the pressure sensors agrees well with the FTIR and XRD characteristics. In our experiments, the measured sensitivity reached up to 30 pC/N for the nanofiber webs containing 1.5 wt% Ag NWs, which is close to that of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE), (77/23)]. This study may provide a new method of fabricating high performance flexible sensors at relatively low cost compared with sensors based on [P(VDF-TrFE), (77/23)].