Asymmetric Modification of Carbazole Based Self-Assembled Monolayers by Hybrid Strategy for Inverted Perovskite Solar...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Carbazole-based self-assembled molecules (SAMs) are crucial for inverted perovskite solar cells (iPSCs).
• Symmetrical SAM structures limit performance tuning, hindering efficiency and stability improvements in iPSCs.

Purpose of the Study:

• To design and synthesize an asymmetric carbazole core (TTID) for SAMs to overcome limitations of symmetrical structures.
• To investigate how the asymmetric core regulates SAM properties and impacts iPSC performance.

Main Methods:

• Synthesis of an asymmetric carbazole core (9H-thieno[2',3':4,5]thieno[3,2-b]indole - TTID).
• Incorporation of TTID into SAMs for iPSCs.
• Characterization of SAM properties (energy levels, wettability, defect passivation) and device performance.

Main Results:

• The asymmetric TTID core effectively regulated SAM energy levels, surface wettability, and defect passivation.
• Substituents on the core significantly influenced molecular dipole and device stability.
• Fluorine incorporation and the thieno[2,3-b]thiophene unit led to a certified power conversion efficiency (PCE) of 25.17% in KF-derived iPSCs.
• Demonstrated excellent operational stability for the developed iPSCs.

Conclusions:

• The asymmetric carbazole core design offers a versatile strategy for optimizing SAMs in iPSCs.
• This hybrid design approach facilitates fine-tuning of SAM properties for enhanced solar cell efficiency and longevity.
• The study presents a promising pathway for advancing SAM development in perovskite solar cell technology.