XPSPeak 4.1 is a widely used, lightweight Windows application designed for the visualization and curve-fitting of X-ray photoelectron spectroscopy (XPS) data. Originally developed by Raymund Kwok, it remains a popular choice for materials scientists and researchers due to its ability to handle complex deconvolution tasks at no cost. Key Features of XPSPeak 4.1

Double-click XPSPEAK41.exe to launch. No formal installation wizard is usually required for the portable version.

A powerful commercial standard for XPS analysis. While paid, it offers a demo version with full fitting features but limited export capabilities.

Ensure the main executable, often represented by an icon with a red peak deconvoluted by two blue peaks, is in the folder alongside its supporting library files.