Thermal Dynamic Self‐Healing Supramolecular Dopant Towards Efficient and Stable Flexible Perovskite Solar Cells

Abstract

Flexible perovskite solar cells (FPSCs) have attracted great attention due to their advantageous traits such as low cost, portability, light-weight, etc. However, mechanical stability is still the weak point in their practical application. Herein, we prepared efficient FPSCs with remarkable mechanical stability by a dynamic thermal selfhealing effect, which can be realized by the usage of a supramolecular adhesive. The supramolecular adhesive, which was obtained by random copolymerization of acrylamide and n-butyl acrylate, is amphiphilic, has a proper glass transition temperature and a high density of hydrogenbond donors and receptors, providing the possibility of thermal dynamic repair of mechanical damage in FPSCs. The adhesive also greatly improves the leveling property of the precursor solution on the hydrophobic poly [bis(4phenyl)(2,4,6-trimethylphenyl)]amine (PTAA) surface. PSCs containing this adhesive achieve more than a 20 % power conversion efficiency (PCE) on flexible substrates and a 21.99 % PCE on rigid substrates (certified PCE of 21.27 %), with improved electron mobility and reduced defect concentration.

Self‐Organized Small Molecules in Robust MOFs for High‐Performance Perovskite Solar Cells with Enhanced Degradation Activation Energy

“…[ 1–7 ] However, the perovskite materials are sensitive to some extreme factors, such as moisture, illumination, and high temperature, due to inherently soft lattice and ionic defects during the low‐temperature crystallization process. [ 8–12 ] Additive engineering has been demonstrated as an effective measure to improve the stability of perovskite film through eliminating the defects at the surface and grain boundaries (GBs) and changing surface structure. [ 13,14 ] Various small organic molecules with electron donor–acceptor functional groups, such as caffeine, theophylline, and capsaicin, show positive effects on passivating positive and negative charged defects when employed as additives.…”

Ionogel-perovskite matrix enabling highly efficient and stable flexible solar cells towards fully-R2R fabrication

“…In terms of efficiency, mechanical stability and operational stability, the IG-PVK devices are at the forefront of the reported flexible PSCs, even compared to spin-coated devices (Table S1, ESI †). [1][2][3][4][5]9,27,28,[37][38][39][40][41][51][52][53][54][55][56] The extensively tunable IG matrix, as a platform containing rich interactions, through its modification and collaboration with perovskite endows flexible devices with robust mechanical properties, inhibition of ion migration, passivation of multiple interfaces, prevention of lead leakage, 57 etc., infinite possibilities. We believe that ionogel will play more important and unique roles on the road to the commercialization of flexible perovskite solar cells.…”

“…[22][23][24][25][26] However, the breaking elongation of these materials is usually low, and damaged materials cannot be repaired or require extra energy input, such as further thermal annealing, to be repaired. 27,28 In addition, the generally poor electrical conductivity of doped polymers creates more insulative grain boundaries and interface, 7,20 which required compromise among the passivation capability (V OC -related), series resistance (FF-related) and grain boundary fracture energy (mechanical stability-related) of the device, and greatly increased the difficulty of molecular design. Thus, it is urgent to develop novel elastic dopants with high elongation as well as preferred easy self-healing ability without sacrificing carrier mobility or the original advantages in the above strategies, which would be highly important towards efficient and stable flexible PSCs.…”

Grain‐Slip Derived Network Topology to Remarkable Strength–Toughness Combination of Perovskite Film for Flexible Solar Cells

“…[28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] However, only around 1.1% elongation at break and fracture strength generally below 50 MPa limit the application of perovskite films in wearable devices. [43][44][45] Although some works attempted to increase the toughness of perovskite films, [46][47][48] the simultaneous improvement of strength and toughness is a huge challenge. In addition, especially for photo electric materials, it is difficult to overcome the conflict of strength and toughness while maintaining high photoelectric properties, such as high carrier mobility.…”