Liquid-Based Multijunction Molecular Solar Thermal Energy Collection Device

Area of Science:

• Materials Science
• Renewable Energy
• Photochemistry

Background:

• Solar thermal energy storage (MOST) offers a promising route for renewable energy utilization.
• Current MOST systems face limitations in energy capture and storage efficiency.
• Photoswitchable molecules are key components for MOST devices.

Purpose of the Study:

• To explore the potential of multijunction MOST devices for enhanced solar energy collection and storage.
• To investigate the impact of combining photoswitches with varying absorption on efficiency limits.
• To demonstrate a proof-of-concept for a multi-layered MOST device.

Main Methods:

• Parametric model calculations were used to predict efficiency limits for double and triple-junction systems.
• Experimental demonstration of a three-layered MOST device using distinct photoswitches.
• Utilized norbornadiene, dihydroazulene, and azobenzene derivatives in liquid state.

Main Results:

• Parametric modeling indicated potential efficiency improvements from 13.0% to 18.2% (double-junction) and 20.5% (triple-junction) with ideal photoswitches.
• A proof-of-concept three-layered device demonstrated enhanced energy capture and storage.
• The study highlights the importance of tailoring molecular properties for specific wavelength absorption.

Conclusions:

• Multijunction designs represent a significant advancement for MOST systems.
• Tailoring photoswitchable molecules for specific absorption profiles is crucial for optimizing MOST efficiency.
• This work introduces a new design paradigm for efficient solar energy storage molecules.