Charge Injection and Electrical Response in Low-Temperature SnO₂-Based Efficient Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Efficient fabrication of perovskite solar cells (PSCs) is crucial for cost-effective production.
• Low-temperature processing methods are desirable for simplifying PSC manufacturing.
• Developing effective electron transporting layers (ETLs) is key to enhancing PSC performance.

Purpose of the Study:

• To establish a low-temperature (123 °C) solution-based protocol for preparing tin oxide (SnO2) ETLs for PSCs.
• To investigate the charge injection dynamics and performance of PSCs utilizing these SnO2 ETLs.
• To analyze the recombination mechanisms and hysteresis behavior in the fabricated PSCs.

Main Methods:

• Solution-based deposition of SnO2 layers at 123 °C.
• Fabrication and characterization of planar perovskite solar cells (PSCs).
• Photoluminescence decay measurements and impedance spectroscopy to study charge dynamics.

Main Results:

• Thin, conformal, and transparent SnO2 ETLs were successfully prepared.
• PSCs achieved a maximum power conversion efficiency (PCE) of 18.22% with low hysteresis (6.7%).
• Fast charge injection into the spiro-OMeTAD layer was observed; SnO2 ETLs exhibited charge injection time constants comparable to benchmark layers.
• Impedance spectroscopy revealed high recombination resistance, contributing to a large open-circuit voltage (Voc) and low hysteresis.

Conclusions:

• The developed low-temperature SnO2 ETL protocol offers a simplified and efficient route for PSC fabrication.
• The optimized SnO2 ETLs contribute to high PCE and improved device stability by minimizing recombination and hysteresis.
• This approach holds promise for the scalable and economical production of high-performance perovskite solar cells.