Atom probe tomography studies on the Cu(In,ga)Se2 grain boundaries.

Area of Science:

• Materials Science
• Nanotechnology
• Solar Cell Technology

Background:

• Characterizing internal interfaces at the nanoscale is crucial for understanding material properties.
• Existing techniques have limitations in sensitivity and spatial resolution for nanoscale interface analysis.
• Cu(In,Ga)Se2 thin films are important for solar cell applications, where grain boundaries affect performance.

Purpose of the Study:

• To demonstrate a site-specific sample preparation method for atom probe tomography (APT).
• To chemically characterize grain boundaries in Cu(In,Ga)Se2 thin films using APT.
• To evaluate the advantages and drawbacks of APT for studying grain boundaries in this material.

Main Methods:

• Site-specific sample preparation utilizing focused-ion-beam (FIB), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM).
• Atom probe tomography (APT) for 3D chemical characterization at the nanoscale.
• Analysis of grain boundaries within Cu(In,Ga)Se2 thin films.

Main Results:

• Successful preparation of APT tips containing specific grain boundaries with known structures.
• APT enabled high-sensitivity (ppm) and high-spatial-resolution (sub-nm) chemical analysis of interfaces.
• Demonstrated feasibility of studying grain boundaries in Cu(In,Ga)Se2 thin films.

Conclusions:

• Atom probe tomography is a powerful technique for nanoscale chemical characterization of internal interfaces.
• The presented site-specific preparation method allows targeted investigation of grain boundaries.
• APT offers significant advantages for understanding structure-property relationships in thin-film solar cells.