Efficient Hole-Transporting Materials with Triazole Core for High-Efficiency Perovskite Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Organic Chemistry

Background:

• Efficient hole-transporting materials (HTMs) are crucial for high-performance perovskite solar cells.
• Current state-of-the-art HTMs like spiro-OMeTAD are often expensive, driving the need for cost-effective alternatives.

Purpose of the Study:

• To synthesize novel donor-acceptor type HTMs with improved hole-transporting properties.
• To investigate the impact of structural modifications, such as thiophene bridging, on HTM performance.
• To evaluate the photovoltaic performance of perovskite solar cells utilizing these new HTMs.

Main Methods:

• Synthesis of two novel HTMs, TAZ-[MeOTPA]2 and TAZ-[MeOTPATh]2, based on a 4-phenyl-1,2,4-triazole core with diphenylamino side arms.
• Characterization of the synthesized HTMs, focusing on their electronic and structural properties.
• Fabrication and testing of perovskite solar cells incorporating the synthesized HTMs and comparison with spiro-OMeTAD.

Main Results:

• The synthesized HTMs, TAZ-[MeOTPA]2 and TAZ-[MeOTPATh]2, demonstrated effective intramolecular charge transfer.
• Perovskite solar cells using these HTMs achieved high power conversion efficiencies of 10.9% and 14.4%, respectively.
• The performance was comparable to cells using the standard spiro-OMeTAD HTM.

Conclusions:

• The novel, synthetically simple, and inexpensive HTMs show significant potential for high-efficiency perovskite solar cells.
• Thiophene bridging in HTMs can enhance intermolecular π-π stacking and spectral response.
• These materials offer a promising and cost-effective alternative to expensive HTMs currently used in the field.