In-depth analysis of CIGS film for solar cells, structural and optical characterization

TL;DR

This paper provides a detailed analysis of CIGS solar cell films, examining their structural and optical properties through advanced characterization techniques to understand stress, texture, and composition gradients.

Contribution

It introduces a comprehensive approach combining X-ray diffraction and photoluminescence to analyze stress, texture, and band gap gradients in CIGS solar cells.

Findings

Stress profiles depend on absorber thickness and are linked to growth dynamics.

Grain texturing correlates with composition gradients and band gap grading.

Optical and structural properties are interconnected through strain and composition profiles.

Abstract

Space-resolved X-ray diffraction measurements performed on gradient-etched CuInGaSe2 (CIGS) solar cells provide information about stress and texture depth profiles in the absorber layer. An important parameter for CIGS layer growth dynamics, the absorber thickness-dependent stress in the molybdenum back contact is analyzed. Texturing of grains and quality of the polycrystalline absorber layer are correlated with the intentional composition gradients (band gap grading). Band gap gradient is determined by space-resolved photoluminescence measurements and correlated with composition and strain profiles.