A shape memory scaffold for body temperature self‐repairing wearable perovskite solar cells with efficiency exceeding 21%

Abstract

Grain boundary cracks in flexible perovskite films can be repaired by filling with self-repairing polymers during the preparation and wearable operation.However, the self-repairing polymers are commonly active through external heating or humidification treatments, which cannot match with the human body's temperature tolerance of wearable devices. Herein, a body temperatureresponsive shape memory polyurethane (SMPU) is demonstrated to achieve the real-time mechanical self-repairing of grain boundary cracks (~37 C). Furthermore, the strong intermolecular interaction between SMPU and the uncoordinated Pb 2+ and I À , can reduce the trap density in perovskite films.The blade-coated device achieves a power conversion efficiency (PCE) of 21.33%, which is among the best reported flexible perovskite solar cells (PSCs; 0.10 cm 2 ). Importantly, the device with SMPU can recover more than 80% of the PCE after 6000 cycles (bending radius: 8 mm). Finally, the flexible PSCs are used for wearable solar power supply of a smartphone, which show great potential for self-repairing wearable electronics.

Surface Cleaning and Passivation Strategy for Durable Inverted Formamidinium–Cesium Triiodide Perovskite Solar Cells

“…Specifically, R s and R rec are the series resistance and the recombination resistance of the devices, respectively. [ 47 ] It shows that the recombination resistance of the clean‐passivate device increases significantly, indicating a suppression of non‐radiative recombination due to defect passivation. Kelvin probe force microscopy (KPFM) also demonstrates that the surface electrical properties of the perovskite has been changed by clean‐passivation method, with more uniform potential distribution, as shown in Figure S20 (Supporting Information).…”

Recent Advances in Quality Strengthening of Perovskite Films by Additive Engineering for Efficient Solar Cells

“…Reproduced with permission. [ 126 ] Copyright 2022, Wiley‐VCH. D) Optical microscope images of the self‐healing process: cracks changed process in the crosslinked TA‐NI film at room temperature (about 35 °C) over time.…”

“…To make FPSCs more suitable for wearable electronic products, Xue et al reported a temperature‐responsive (37 °C) shape memory polyurethane (SMPU) for real‐time self‐healing of FPSCs grain boundary cracks. [ 126 ] In addition, SMPU is uniformly distributed at the grain boundaries of the perovskite film to form a crosslinked network, which enhances the grain size and passivates the grain boundary defects and greatly releases the mechanical stress (Figure 9C). Therefore, the leaf‐coated FPSCs with SMPU achieved a 21.33% champion PCE.…”

Freely-shapable fabrication of aerogel patterns and 3D architectures by freeze-assisted transfer printing

“…[5][6][7][8][9] Their superior mechanical, thermal, and conductive performance provides a broad application prospect in energy storage, pollutant adsorption, heat insulation, electromagnetic shielding, flexible sensing, catalysis and other fields. [10][11][12][13][14][15] Graphene aerogel is a kind of macroscopic material assembled from graphene or its derivatives, with an interconnected porous network structure, which is also known as graphene foam or graphene sponge. Although the bulk form of graphene aerogel has shown functional applications in many aspects, its development from a macroscopic scale toward miniaturized patterns is of great importance for the realization of high-performance integrated devices.…”