# TUNA‐EBSD‐CL correlative multi‐microscopy study, on the example of Cu(In,Ga)S2 solar cell absorber

## TL;DR

This study shows how to best combine multiple microscopy techniques to understand the structure and properties of solar cell materials.

## Contribution

The paper introduces an optimized measurement order for multi-microscopy to avoid contamination effects and improve data quality.

## Key findings

- Measurement order affects dataset quality due to surface contamination.
- TUNA-EBSD-CL order minimizes contamination effects.
- Local electrical and opto-electronic properties correlate with grain boundary microstructure.

## Abstract

Multi‐microscopy offers significant benefits to the understanding of complex materials behaviour by providing complementary information from different properties. However, some characterisations may strongly influence other measurements in the same workflow. To acquire reliable and valid datasets, optimising multi‐microscopy procedure is necessary. In present work, we studied the influence of the measurement order on the quality of multi‐microscopy datasets. Multi‐microscopy incorporating tunnelling current AFM (TUNA), electron backscatter diffraction (EBSD), and cathodoluminescence (CL) on a polycrystalline solar cell absorber, Cu(In,Ga)S2 (CIGS), is used as an example. The investigation revealed potential characterisation‐induced contaminations, such as surface oxidation and hydrocarbon layer coating, of the sample surface. Their subsequent influence on the measurement results of following correlation techniques was examined. To optimise the dataset quality, multi‐microscopy should be carried out in TUNA‐EBSD‐CL order, from the most to the least surface sensitive techniques. With the optimised multi‐microscopy measurement order on a CIGS absorber, we directly correlated the local changes in electrical and opto‐electronic properties with the microstructure of grain boundaries (GBs). The described methodology may also provide insightful concepts for applying other AFM‐SEM‐based multi‐microscopy on different semiconductor materials.