Visualizing SolarCells at Work: An in Situ SampleHolder for Multimodal X-ray Nanoscopy under Realistic OperatingConditions

Here, we report the design, construction, and commissioning of a photovoltaic holder for in situ and operando characterization of solar cells at the TARUMÃ end station of the X-ray nanoprobe CARNAÚBA at the SIRIUS synchrotron light source of LNLS/CNPEM. The holder enables the investigation of complete solar cells using X-ray microscopy techniques. It was developed with precision-engineering design principles to achieve nanometer-level position stability and minimize thermal drift. The holder also allows precise control of temperature in the target area, atmosphere, illumination, and bias. These features enable the simulation of real solar cell operation. The holder supports various X-ray-based techniques, such as X-ray fluorescence, X-ray diffraction, and X-ray absorption spectroscopy, all with nanoscale capabilities. Infrared images revealed a homogeneous temperature distribution inside the 3 × 3 mm target area. During heating, horizontal displacement was minimal. Vertical displacement reached 5 μm at 120 °C but was reversible upon returning to room temperature. At stable temperatures, the holders showed better position stability than the beam size. Photovoltaic characterization was demonstrated, along with chemical structural mapping using X-ray microscopy for different techniques. In summary, this paper presents an in situ and operando platform for correlative chemical-structural nanoscale mapping of solar cells using multiple techniques with controlled environmental parameters.