Optimal CdS Buffer Thickness to Form High-Quality CdS/Cu(In,Ga)Se₂ Junctions in Solar Cells without Plasma Damage and...

Area of Science:

• Materials Science
• Renewable Energy Technologies
• Semiconductor Physics

Background:

• Cadmium sulfide (CdS) is a key junction partner for copper indium gallium selenide (CIGS) in CIGS solar cells.
• Thick CdS buffers reduce short-circuit current density, while ultrathin buffers face plasma damage and low shunt resistance issues.
• Existing methods often require thicker CdS than optimal to mitigate these challenges.

Purpose of the Study:

• To determine the minimum CdS buffer thickness for high-performance CIGS solar cells.
• To eliminate plasma damage and shunt paths using silver nanowire window layers.
• To optimize the CdS buffer layer for improved device efficiency.

Main Methods:

• Investigated the impact of varying CdS buffer layer thicknesses on CIGS solar cell performance.
• Utilized silver nanowire-based window layers to address plasma damage and shunt resistance.
• Analyzed device parameters including short-circuit current density, fill factor, and open-circuit voltage.

Main Results:

• An approximately 13 nm CdS buffer layer achieved high short-circuit current density and fill factor.
• An additional 13 nm CdS buffer (totaling ~26 nm) was required to maximize open-circuit voltage.
• A ~26 nm CdS buffer layer proved sufficient for forming a high-quality CdS/CIGS junction.

Conclusions:

• A ~26 nm CdS buffer layer is optimal for CIGS solar cells utilizing silver nanowire window layers.
• This optimized thickness mitigates plasma damage and shunt resistance without sacrificing device performance.
• The findings provide a pathway for efficient and high-performance CIGS solar cell fabrication.