Polycarbazole-SAM Hybrid Interface Engineering for Efficient Hole Extraction in Perovskite Photovoltaic Devices

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Self-assembled monolayers (SAMs) on nickel oxide are crucial for hole-selective contacts in perovskite solar cells (PSCs).
• Interfacial challenges like incomplete coverage and aggregation limit SAM performance and device stability.
• Nickel oxide (NiOx) is a common p-type semiconductor used in PSCs.

Purpose of the Study:

• To develop a hybrid interfacial architecture combining SAMs and poly(vinylcarbazole) (PVK) for improved PSCs.
• To address limitations of SAMs, such as coverage and aggregation, for enhanced device performance.
• To investigate the synergistic effects of PVK and SAMs on interfacial properties and charge transport.

Main Methods:

• Fabrication of a hybrid interface integrating SAMs with PVK on nickel oxide substrates.
• Characterization of the interface using techniques to assess SAM coverage, energy level alignment, and recombination suppression.
• Fabrication and testing of p-i-n perovskite solar cells utilizing the novel hybrid interface.

Main Results:

• The PVK-SAM hybrid interface promoted uniform SAM coverage and optimized energy level alignment.
• Nonradiative recombination was effectively suppressed, leading to improved charge carrier dynamics.
• PVK chains formed an interpenetrating network, facilitating efficient hole extraction.
• Perovskite solar cells achieved a champion power conversion efficiency exceeding 23% with enhanced operational stability.

Conclusions:

• The PVK-SAM hybrid strategy offers a promising approach to overcome SAM limitations in PSCs.
• This interfacial engineering enhances device efficiency and stability by improving hole extraction and reducing recombination.
• The developed hybrid interface presents a new design paradigm for high-performance p-i-n perovskite solar cells.