Supramolecular Polyurethane “Ligaments” Enabling Room‐Temperature Self‐Healing Flexible Perovskite Solar Cells and Mini‐Modules

Abstract

Flexible perovskite solar cells (F‐PSCs) have emerged as promising alternatives to conventional silicon solar cells for applications in portable and wearable electronics. However, the mechanical stability of inherently brittle perovskite, due to residual lattice stress and ductile fracture formation, poses significant challenges to the long‐term photovoltaic performance and device lifetime. In this paper, to address this issue, a dynamic “ligament” composed of supramolecular poly(dimethylsiloxane) polyurethane (DSSP‐PPU) is introduced into the grain boundaries of the PSCs, facilitating the release of residual stress and softening of the grain boundaries. Remarkably, this dynamic “ligament” exhibits excellent self‐healing properties and enables the healing of cracks in perovskite films at room temperature. The obtained PSCs have achieved power conversion efficiencies of 23.73% and 22.24% for rigid substrates and flexible substrates, respectively, also 17.32% for flexible mini‐modules. Notably, the F‐PSCs retain nearly 80% of their initial efficiency even after subjecting the F‐PSCs to 8000 bending cycles (r = 2 mm), which can further recover to almost 90% of the initial efficiency through the self‐healing process. This remarkable improvement in device stability and longevity holds great promise for extending the overall lifetime of F‐PSCs.

Enhanced Perovskite Photovoltaics with Non-conjugated Polymers: Recent Developments and Future Prospects

“…While PU with dynamic disulfide bonds may require heating for self-healing, the quest for developing self-healing perovskite materials that can repair themselves at ambient conditions is ongoing. Yang et al 63 introduced a dynamic "ligament" composed of supramolecular polydimethylsiloxane polyurethane (DSSP-PPU) into the grain boundary of PSC. This dynamic "ligament" promotes the release of residual stress and the softening of the grain boundary.…”

“…(d) Self-healing process based on supramolecular “ligament” DSSP-PPU. Reproduced with permission from ref . Copyright 2024 Wiley-VCH.…”

Silane Doping for Efficient Flexible Perovskite Solar Cells with Improved Defect Passivation and Device Stability

“…The rough surface tends to generate a large number of nucleation sites, , leading to overcrystallization and the formation of multisized perovskite grains, which in turn affects the crystalline quality and morphology of the films. All those derived defects may become carrier complexation centers, causing nonradiative recombination losses and generating residual stresses, − thus reducing the power conversion efficiency (PCE) of the device, as the perovskite material in the light-absorbing layer is prone to absorbing moisture in the air, − leading to the production of defects from oxidation, which provide pathways for the infiltration of water and oxygen, accelerating the decomposition of the perovskite layer and degradation of devices . Therefore, the formation of high-quality perovskite films with dense, smooth surfaces and pinhole-free properties is crucial to realizing efficient devices.…”