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

Abstract

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 FA0.92MA0.08PbI3 perovskite by doping an organic ferroelectric material, poly(vinylidene fluoride):dabcoHReO4 (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. The BEF superposition can more sufficiently drive the charge‐carrier transport and extraction, thus suppressing the nonradiative recombination occurring in the pero‐SCs. Moreover, the PVDF:DH dopant benefits the formation of a mesoporous PbI2 film, via a typical two‐step processing method, thereby promoting perovskite growth with high crystallinity and a few defects. The resulting pero‐SC shows a promising PCE of 24.23% for a 0.062 cm2 device (certified PCE of 23.45%), and a remarkable PCE of 22.69% for a 1 cm2 device, along with significantly improved moisture resistances and operational stabilities.

Surface Re-Engineering of Perovskites with Buckybowls to Boost the Inverted-Type Photovoltaics

“…Studies on Molecular Behaviors of the ACIs on a Perovskite Surface. In view of the strong impact of the interfacial dipole on the charge extraction, 40 it is crucial to gain insight into the molecular behaviors of the ACIs assembled on the perovskite surface. Targeting on investigating chemical interaction between ACI molecules and perovskites, we managed to perform the X-ray photoelectron spectroscopy (XPS) measurements of different films, as shown in Figure 2.…”

Modulation of nucleation and crystallization in PbI2 films promoting preferential perovskite orientation growth for efficient solar cells

“…Several works have been reported to alter the porosity of PbI 2 and the crystallization process of perovskites for the growth of high-quality perovskite films. 17,20,21,23–26 For example, Liu and co-workers introduced 1-naphthalenemethylammonium iodide (NpMAI) or two-dimensional (2D) (NpMA) 2 PbI 4 perovskites to regulate the crystal growth in 2D/three-dimensional (3D) perovskite films. 21 The treated PbI 2 films were mesoporous, which allowed full penetration of the ammonium salts and improved the quality of the 2D/3D perovskite films.…”

Enhancing the Piezoelectric Sensing of CFO@PDA/P(VDF-TrFE) Composite Films through Magnetic Field Orientation

“…As a typical piezoelectric polymer material, PVDF has a complex crystal structure consisting of microcrystalline regions dispersed in amorphous regions. Pure PVDF polymer can only be forced to transform into the electroactive β-phase under certain conditions, such as mechanical stretching, polarization, electrostatic spinning, doping, etc. Compared with PVDF, P­(VDF-TrFE) is relatively easy to crystallize to achieve a polar β-phase.…”