Singlet Fission in 9,10-Bis(phenylethynyl)anthracene Thin Films.

Area of Science:

• Materials Science
• Photochemistry
• Organic Electronics

Background:

• Singlet fission (SF) is a process converting a singlet exciton into two triplet excitons, enhancing solar cell efficiency.
• Existing SF materials often lack stability and possess low triplet energies, limiting their use in devices.
• Organic chromophores are key to developing efficient solar energy conversion technologies.

Purpose of the Study:

• To investigate the potential of 9,10-bis(phenylethynyl)anthracene (BPEA) for singlet fission applications.
• To analyze the SF efficiency and kinetics in polycrystalline BPEA thin films.
• To evaluate BPEA as a candidate for improving solar cell performance.

Main Methods:

• Characterization of polycrystalline BPEA thin films.
• Spectroscopic analysis to determine singlet and triplet energies.
• Kinetics studies to measure SF rates (kSFA and kSFB).
• Determination of triplet yields.

Main Results:

• Efficient singlet fission was observed in BPEA polycrystalline thin films.
• BPEA exhibits high singlet (2.40 eV) and triplet (1.11 eV) energies in the solid state.
• Two polymorphs of BPEA (C2/c and Pbcn) showed distinct SF rates: kSFA = (109 ± 4 ps)⁻¹ and kSFB = (490 ± 10 ps)⁻¹.
• A high triplet yield of 180 ± 20% was measured.

Conclusions:

• 9,10-bis(phenylethynyl)anthracene (BPEA) demonstrates efficient singlet fission in polycrystalline thin films.
• The high triplet energy and efficient SF process make BPEA a promising material for next-generation solar cells.
• BPEA's properties suggest potential for enhancing solar energy conversion efficiency in practical devices.