Highly (100)-oriented CH₃NH₃PbI₃(Cl) perovskite solar cells prepared with NH₄Cl using an air blow method

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells are promising for next-generation photovoltaics.
• Controlling perovskite film morphology and crystal orientation is crucial for device performance and stability.

Purpose of the Study:

• To investigate the impact of ammonium chloride (NH4Cl) addition through an air blow process on CH3NH3PbI3(Cl) perovskite solar cells.
• To optimize the fabrication process for improved efficiency and stability.

Main Methods:

• Fabrication of CH3NH3PbI3(Cl) solar cells using spin-coating with varying NH4Cl concentrations.
• Microstructural analysis using X-ray diffraction (XRD), optical microscopy, and scanning electron microscopy (SEM).
• Evaluation of current density-voltage (J-V) characteristics and photoconversion efficiency.

Main Results:

• Addition of an appropriate amount of NH4Cl and air blowing significantly improved cell performance.
• Photoconversion efficiency reached 14% due to enhanced current density-voltage characteristics.
• Microstructural analysis revealed dense perovskite grains with a strong (100) orientation, indicated by a 2000-fold increase in the (100)/(210) reflection intensity ratio.
• The fabricated devices demonstrated stability upon storage in ambient air for two weeks.

Conclusions:

• NH4Cl addition via air blowing is an effective method for enhancing the performance and stability of CH3NH3PbI3(Cl) perovskite solar cells.
• The improved efficiency is attributed to the formation of dense perovskite films with preferred (100) crystal orientation.
• The process offers a viable route for developing efficient and stable perovskite solar cell technologies.