Enhancing perovskite solar cells efficiency via dual surface passivation.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Effective defect passivation is crucial for high-performance perovskite solar cells (PSCs).
• Dimensional engineering is a key strategy to minimize recombination losses in PSCs.
• The perovskite/hole transport layer interface is a critical area for passivation.

Purpose of the Study:

• To introduce a novel interfacial passivation strategy for PSCs using a dual-cation approach.
• To investigate the impact of guanidinium bromide (GuaBr) and n-phenylethylammonium bromide (n-PEABr) on PSC efficiency and stability.
• To compare the performance of dual-cation passivation with single-cation methods.

Main Methods:

• Fabrication of PSCs employing a dual-cation passivation layer at the perovskite/hole transport layer interface.
• Characterization of the perovskite film morphology and surface properties.
• Performance evaluation of the devices, including open-circuit voltage (Voc) and power conversion efficiency (PCE).
• Assessment of device stability under ambient conditions (80% relative humidity) and continuous light-soaking.

Main Results:

• The dual-cation passivation layer achieved an open-circuit voltage of 1.23 V and a PCE of 25.11%.
• This dual-cation strategy resulted in a mixed 1D/2D perovskite structure, leading to more uniform and hydrophobic surfaces.
• Devices exhibited significantly enhanced stability under both humidity and light-soaking stress.
• The PCE exceeded 25%, surpassing previous passivation methods like octylammonium.

Conclusions:

• The dual-cation passivation strategy effectively suppresses non-radiative recombination in PSCs.
• n-phenylethylammonium bromide demonstrates superior passivation capabilities compared to previously reported methods.
• This approach offers a promising pathway for developing highly efficient and stable perovskite solar cells.