Lead-Sealed Stretchable Underwater Perovskite-Based Optoelectronics via Self-Recovering Polymeric Nanomaterials

Abstract

To harness the full potential of halide perovskite based optoelectronics, biological safety, compatibility with flexible/ stretchable platforms, and operational stability must be guaranteed. Despite substantial efforts, none has come close to providing a solution that encompasses all of these requirements. To address these issues, we devise a multifunctional encapsulation scheme utilizing hydrogen bond-based self-recovering polymeric nanomaterials as an alternative for conventional glass-based encapsulation. We show that Pb in physically damaged halide perovskite solar cells can be completely contained within the self-recovering encapsulation upon submersion in a simulated rain bath, as indicated by in vitro cytotoxicity tests. In addition, self-recovering encapsulation accommodates stable device operation upon casual bending and even stretching, which is in stark contrast to conventional glass-based encapsulation schemes. We also demonstrate the concept of assembling user-defined scalable modular optoelectronics based on halide perovskite solar cells and light emitting diodes through the use of self-recovering conductive nanocomposites. Finally, long-term operational stability of over 1000 h was achieved under harsh accelerated conditions (50 °C/50% RH and 85 °C/0% RH) with the incorporation of an ultrathin atomic layer deposited TiO 2 barrier underneath the multifunctional encapsulation. In light of these merits, the encapsulation scheme based on self-recovering polymeric nanomaterials is proposed as a simple, but practical solution to a multifaceted challenge in the field of halide perovskites.

The issues on the commercialization of perovskite solar cells

“…Different from most self-healing polymers, which are not suitable for stability improvement due to their substantial water vapor transmission rate, the hydrophobic tough self-healing polymer with dynamic multivalent hydrogen bonds and the low T g enable self-healing without external stimuli. As a representative work, Kim's group tailored PDMS-MPU 0.4 -IU 0.6 hydrophobic tough self-healing polymer by incorporating strong hydrogen bonded 4,4 ′ -methylenebis(phenylisocyanate) (MPU) and hydrophobic isophorone diisocyanate (IU) with PDMS [199]. By using it as encapsulation material, the broken polymer films can reconnect in ambient air or even in water, and the connected films have very good stretchability.…”

Materials, Device Structures, and Applications of Flexible Perovskite Light‐Emitting Diodes

“…[39] By changing the elemental species in the perovskite materials, the optical/electrical properties and stability of perovskites can be significantly tuned, which suggests their great potential of high material tenability for device applications. [40][41][42] In addition, owing to the high defect tolerance of perovskite materials, various elements can be selected and applied at different sites to obtain various perovskite materials with controlled optical properties. [43] The crystal structure of perovskites is sensitive to the ionic radius of the A-site cations because of the limitation of the octahedral [BX 6 ] 4− framework, which can greatly affect the stability of perovskites.…”

Mitigating Potential Lead Leakage Risk of Perovskite Solar Cells by Device Architecture Engineering from Exterior to Interior

“…Kim et al developed a selfrecovering polymeric nanomaterials (SRPs) encapsulant. 114 The SRPs have low T g (with self-recovering capabilities even at 0 °C) so the self-recovery process occurs without external stimuli even when the devices are submerged underwater. To test its Pb sequestration efficacy, the damaged PSCs were soaked in water baths containing simulated acidic (pH = 6.0) and alkaline (pH = 8.2) rain for 24 h. The concentrations of Pb in acid and alkaline rain baths were 0.61 and 1.73 ppb, respectively, which are 3−4 magnitude lower than PSCs with conventional glass-based encapsulation (5.6 and 6.1 ppm, respectively).…”

“…However, it may fail in the extreme case when the weather is rainy or snowy and the T g of ER may never be reached. Kim et al developed a self-recovering polymeric nanomaterials (SRPs) encapsulant . The SRPs have low T g (with self-recovering capabilities even at 0 °C) so the self-recovery process occurs without external stimuli even when the devices are submerged underwater.…”