A comparative study on hydroxyl and ether functionalized ionic liquid additives for defect passivation and stability...

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Triple-cation perovskite solar cells offer high efficiency but face challenges in stability and morphology control.
• Ionic liquids (ILs) are explored as additives to improve perovskite film quality and device performance.

Purpose of the Study:

• To investigate the impact of two specific ionic liquid additives, EtAI and HOAI, on perovskite thin films.
• To analyze how these additives affect structural, morphological, optical, and photovoltaic properties.
• To determine the optimal additive concentration for enhanced efficiency and long-term stability.

Main Methods:

• Characterization techniques: FT-IR, XRD, XPS, SEM, AFM for structural and morphological analysis.
• Optical property evaluation: UV-Vis, Photoluminescence (PL), Time-Resolved Photoluminescence (TRPL).
• Photovoltaic performance testing: Power Conversion Efficiency (PCE) measurements and stability tests under ambient conditions.

Main Results:

• HOAI and EtAI additives improved perovskite film morphology by increasing grain size, reducing surface roughness, and refining grain boundaries.
• The film with 3 mmol HOAI achieved a maximum PCE of 17.65% and retained 85% efficiency after 1000 hours.
• The film with 1 mmol EtAI reached a PCE of 17.17%, but higher concentrations reduced stability.

Conclusions:

• Hydroxyl groups in HOAI and etheric groups in EtAI are crucial for improving perovskite film quality and charge transport.
• Ionic liquid additives present a viable strategy for enhancing both the efficiency and operational stability of perovskite solar cells.
• This research offers insights into additive chemistry for advancing perovskite solar cell technology.