All-weather photothermal-electric conversion system with multimodal modulation based on an MXene patterned self-adaptive absorber/emitter

Addressing the critical need for 24-hour electricity generation without energy storage, this study presents an MXene-patterned self-adaptive absorber/emitter (MX-SAAE) integrated with VO₂ phase-change material for efficient all-weather photothermal-electric power generation. Patterned MXene boosts broadband solar absorption through localized surface plasmon resonance, while VO₂ drives self-adaptive spectral transitions via the atmospheric window. The system dynamically switches between daytime low-emittance (Low-e) mode and nighttime high-emittance (High-e) mode, enabling continuous operation. The multi-objective optimization of MX-SAAE yields Pareto solutions under different weights of the optimization objectives, which can provide a basis for objective trade-offs in different scenarios and requirements. The optimized MX-SAAE exhibits remarkable angular and polarization insensitivity, maintaining stable performance under incident angles up to 80°. Based on the photothermal-electric coupling cross-scale model established in this paper, daytime power density of 2508 mW/m² and nighttime output of 47 mW/m² can be achieved. The 24-hour real-time performance on typical dates confirmed the effectiveness of the proposed storage-free all-weather photothermal-electric conversion system, which provides a scalable off-grid energy harvesting platform.