Slow-Release Effect Assisted Crystallization for Sequential Deposition Realizes Efficient Inverted Perovskite Solar...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Two-step sequential deposition is common for perovskite solar cells (PSCs).
• Rapid reactions in this method lead to crystal defects and lower efficiency.
• Controlling crystal growth is crucial for high-performance PSCs.

Purpose of the Study:

• To regulate perovskite crystal growth in a two-step deposition method.
• To improve the power conversion efficiency (PCE) and stability of PSCs.
• To investigate the effect of 1-naphthylmethylammonium bromide (NMABr) on perovskite crystallization.

Main Methods:

• Incorporation of 1-naphthylmethylammonium bromide (NMABr) into the organic salt mixture during two-step deposition.
• Analysis of crystal growth dynamics and defect mitigation.
• Performance testing of the enhanced perovskite solar cells (PSCs).

Main Results:

• NMABr addition delayed organic salt aggregation and crystallization, promoting optimal (001) perovskite orientation.
• The "slow-release effect assisted crystallization" strategy was defined.
• Band gap expansion and reduced non-radiative recombination due to Br incorporation.
• Achieved a power conversion efficiency (PCE) of 20.20%.
• Enhanced humidity resistance, with perovskite phase stability exceeding 3000 hours (30-40% RH).

Conclusions:

• The "slow-release effect assisted crystallization" using NMABr is an effective strategy for improving PSC performance.
• NMABr incorporation enhances both efficiency and long-term operational stability of PSCs.
• Hydrophobic naphthalene moiety contributes to improved humidity resistance in PSCs.