Polymorphic Heterogeneous Polar Structure Enabled Superior Capacitive Energy Storage in Lead-Free Relaxor Ferroelectrics at Low Electric Field.

High-performance energy storage dielectrics capable of low/moderate field operation are vital in advanced electrical and electronic systems. However, in contrast to achievements in enhancing recoverable energy density (W), the active realization of superior W and energy efficiency (η) with giant energy-storage coefficient (W/E) in low/moderate electric field (E) regions is much more challenging for dielectric materials. Herein, lead-free relaxor ferroelectrics are reported with giant W/E designed with polymorphic heterogeneous polar structure.

Organic-semiconductor-assisted dielectric screening effect for stable and efficient perovskite solar cells.

Perovskite solar cells (pero-SCs) performance is essentially limited by severe non-radiative losses and ion migration. Although numerous strategies have been proposed, challenges remain in the basic understanding of their origins. Here, we report a dielectric-screening-enhancement effect for perovskite defects by using organic semiconductors with finely tuned molecular structures from the atoms level.

High-Polarizability Organic Ferroelectric Materials Doping for Enhancing the Built-In Electric Field of Perovskite Solar Cells Realizing Efficiency over 24.

The built-in electric field (BEF) intensity of silicon heterojunction solar cells can be easily enhanced by selective doping to obtain high power conversion efficiencies (PCEs), while it is challenging for perovskite solar cells (pero-SCs) because of the difficulty in doping perovskites in a controllable way. Herein, an effective method is reported to enhance the BEF of FA MA PbI perovskite by doping an organic ferroelectric material, poly(vinylidene fluoride):dabcoHReO (PVDF:DH) with high polarizability, that can be driven even by the BEF of the device itself. The polarization of PVDF:DH produces an additional electric field, which is maintained permanently, in a direction consistent with that of the BEF of the pero-SC.