Performance Enhancement of Solution-Processed Submicrometer CISSe Solar Cells via Rear Interfacial Passivation and...

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Solution-processed copper indium sulfoselenide (CISSe) absorbers offer sustainable and scalable solar cell fabrication.
• Carbon residual layers in solution-processed absorbers limit device efficiency.
• Nonradiative recombination losses reduce the performance of solar cells.

Purpose of the Study:

• To develop a high-quality CISSe absorber without a carbon residual layer using a novel solution.
• To mitigate nonradiative recombination by incorporating silica nanospheres.
• To enhance the overall photovoltaic performance of CISSe solar cells.

Main Methods:

• Fabrication of CISSe absorbers using a copper-indium-thiourea-N,N-dimethylformamide (Cu-In-TU-DMF) solution.
• Incorporation of randomly distributed silica (SiO2) nanospheres (250 nm diameter) near the rear absorber interface.
• Passivation of the rear interface with SiO2 nanospheres in semitransparent CISSe devices on indium tin oxide (ITO) back contacts.

Main Results:

• Achieved a champion device efficiency of 9.9% for CISSe solar cells.
• Improved open-circuit voltage (Voc) to 496.2 mV, short-circuit current density (Jsc) to 29.4 mA/cm2, and fill factor (FF) to 67.6%.
• Demonstrated enhanced photovoltaic parameters in semitransparent devices with SiO2 nanosphere passivation.

Conclusions:

• Embedding SiO2 nanospheres is an effective strategy to enhance the performance of solution-processed CISSe solar cells.
• The method successfully addresses carbon residual layers and mitigates nonradiative recombination.
• This approach is applicable to various solution-based photovoltaic technologies, including perovskite solar cells.