Photochromism-Driven Full Solar Spectrum Absorption for Efficient Photo-Thermo-Electric Conversion

Area of Science:

• Materials Science
• Energy Harvesting
• Photothermal Conversion

Background:

• Full solar spectrum absorbing photothermal materials are crucial for solar energy utilization in various applications.
• Current composite materials have limitations in open-circuit voltage and power density.
• Single-component materials often have narrow absorption ranges and complex synthesis.

Purpose of the Study:

• To develop a novel material for efficient solar energy harvesting.
• To overcome the limitations of existing photothermal materials.
• To explore a new photochromic strategy for enhanced photo-thermo-electric conversion.

Main Methods:

• Synthesized a viologen-based organic compound with a π-stacked supramolecular structure.
• Investigated its full solar spectrum absorption (250-2500 nm) and near-infrared (NIR) photothermal conversion efficiency (PCE).
• Integrated the material with a commercial thermoelectric generator (TEC1-12701).

Main Results:

• The viologen compound exhibited full solar spectrum absorption and high NIR PCE (>60%) via photochromism.
• The integrated device achieved an open-circuit voltage of 292.3 mV.
• A power density of 1.30 W·m⁻² was recorded under 1 Sun irradiation.

Conclusions:

• The developed photochromic strategy offers a new pathway for efficient photo-thermo-electric conversion.
• Viologen-based organic compounds show promise for advanced solar energy harvesting applications.
• This research advances the development of materials for wearable electronics and aerospace energy needs.