Star-Shaped Molecules as Dopant-Free Hole Transporting Materials for Efficient Perovskite Solar Cells: Multiscale...

Area of Science:

• Materials Science
• Computational Chemistry
• Renewable Energy

Background:

• Perovskite solar cells (PSCs) require efficient hole transport materials (HTMs) for optimal performance.
• Current HTMs often rely on dopants, which can compromise long-term stability.
• Developing stable, dopant-free HTMs is crucial for advancing PSC technology.

Purpose of the Study:

• To theoretically design and evaluate novel star-shaped molecules as dopant-free HTMs for PSCs.
• To investigate the influence of molecular structure on HTM properties, including electronic, optical, and stability aspects.
• To establish a reliable structure-property relationship for designing next-generation HTMs.

Main Methods:

• Theoretical design of star-shaped molecules (TCP-OH, TPAP-OH, TBOPP-OH) with a phenol core.
• Multiscale simulations to assess molecular properties: frontier molecular orbital, absorption spectrum, hole mobility.
• Adsorption studies of HTM@CH3NH3PbI3 systems to evaluate performance in a realistic environment.
• Simulation of glass transition temperature to determine amorphous film stability.
• Evaluation of both chemical and amorphous film stability.

Main Results:

• Designed molecules TPAP-OH and TBOPP-OH show promising properties as dopant-free HTMs.
• Adsorption studies indicate the influence of the perovskite interface on HTM performance.
• Simulations predict good amorphous film stability for the designed HTMs.
• The study highlights the importance of considering amorphous film stability in HTM evaluation.

Conclusions:

• The designed star-shaped molecules exhibit potential for use as stable, dopant-free HTMs in perovskite solar cells.
• The integrated approach of evaluating isolated molecules and adsorbed systems provides a robust method for assessing HTM candidates.
• This work contributes to building reliable structure-property relationships for future HTM development.