A Solution-Processed Transparent NiO Hole-Extraction Layer for High-Performance Inverted Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Perovskite solar cells (PSCs) are a promising renewable energy technology.
• Efficient hole transport layers (HTLs) are crucial for optimizing PSC performance.
• Conventional methods for preparing NiO HTLs can be complex and less efficient.

Purpose of the Study:

• To develop a highly transparent and efficient nickel oxide (NiO) hole transport layer (HTL) using a simple solution processing method.
• To investigate the impact of the solution-processed NiO HTL on the performance of perovskite solar cells.
• To compare the efficiency of PSCs utilizing the novel NiO HTL with those using conventional sol-gel processed NiO.

Main Methods:

• Preparation of a highly transparent NiO layer via solution processing using nickel(II) 2-ethylhexanoate in a non-polar solvent.
• Integration of the solution-processed NiO layer as a hole transport material (HTM) in perovskite solar cells.
• Characterization of optical transmittance, energy level alignment, and device performance, including power conversion efficiency (PCE).

Main Results:

• The solution-processed NiO layer exhibited excellent optical transmittance.
• The energy levels of the solution-processed NiO were well-matched with the perovskite active layer.
• Perovskite solar cells utilizing the solution-processed NiO HTM achieved a significantly enhanced power conversion efficiency (PCE) of 18.15%.
• This represents a substantial improvement compared to conventional sol-gel processed NiO-based devices, which achieved 12.98% PCE.

Conclusions:

• Solution processing of NiO offers a viable and effective route for fabricating high-performance hole transport layers for perovskite solar cells.
• The enhanced optical transmittance and favorable energy level alignment of the solution-processed NiO contribute to improved device efficiency.
• This approach provides a pathway towards more efficient and potentially lower-cost perovskite solar cell fabrication.