Wearable perovskite solar cells by aligned liquid crystal elastomers

Abstract

In a flexible perovskite solar cell, the bottom interface between perovskite and the electron-transporting layer is critical in determining its efficiency and reliability. High defect concentrations and crystalline film fracturing at the bottom interface substantially reduce the efficiency and operational stability. In this work, a liquid crystal elastomer interlayer is intercalated into a flexible device with the charge transfer channel toughened by the aligned mesogenic assembly. The molecular ordering is instantly locked upon photopolymerization of liquid crystalline diacrylate monomers and dithiol-terminated oligomers. The optimized charge collection and the minimized charge recombination at the interface boost the efficiency up to 23.26% and 22.10% for rigid and flexible devices, respectively. The liquid crystal elastomer-induced suppression of phase segregation endows the unencapsulated device maintaining >80% of the initial efficiency for 1570 h. Moreover, the aligned elastomer interlayer preserves the configuration integrity with remarkable repeatability and mechanical robustness, which enables the flexible device to retain 86% of its original efficiency after 5000 bending cycles. The flexible solar cell chips are further integrated into a wearable haptic device with microneedle-based arrays of sensors to demonstrate a pain sensation system in virtual reality.

Self-healing ion-conducting elastomer towards record efficient flexible perovskite solar cells with excellent recoverable mechanical stability

“…2g is a schematic diagram of the carrier transfer process between perovskite grains, indicating that the reduction potential difference of the grain boundaries will effectively improve the charge transfer efficiency in the perovskite film. 25…”

In Situ Thermal Cross-Linking of 9,9′-Spirobifluorene-Based Hole-Transporting Layer for Perovskite Solar Cells

“…In contrast, under the same conditions, the efficiency of the device using the cross-linked V1382 /dithiol interlayer still retained 71%. Since the cross-linked V1382 /dithiol with a water contact angle of 69° (Figure S23) shows similar hydrophobicity to doped Spiro-OMeTAD , , the better stability of the cross-linked V1382 /dithiol-based PSCs could be attributed to the suppression of the metal diffusion and the interfacial defect passivation, , caused by the insertion of the sulfur-rich interlayer.…”

Molecular dipole engineering-assisted strain release for mechanically robust flexible perovskite solar cells

“…3–6 Therefore, mechanical endurance and long-term operational stability, which can be attributed to defects in the perovskite layer in typical f-PSCs, limit their commercialization. 7–9 Although the PCEs of f-PSCs have been greatly improved, their efficiency significantly lags behind that of their rigid counterparts. 10–13…”