Perovskite studies with microspectrophotometers: why they matter and how to do them

Perovskite materials are known for their strong light absorption and tunable emission, which is why they are widely studied for use in solar cells, LEDs, and other optoelectronic devices. However, anyone working with perovskites soon discovers their behavior is rarely uniform. Small variations in grain structure, composition, or thickness can change how the perovskite sample behaves, ultimately altering the results of a study. Traditional optical measurements often miss the differences between individual regions of a perovskite film, limiting the insight researchers can gain about how the material truly behaves. Such complexities demand spatially resolved measurements, and these can be provided through microspectrophotometers. They can measure optical properties within specific microsized regions, ensuring researchers have direct access to the optical signatures of individual grains, grain boundaries, and other microstructural features that define perovskite materials.

Why microspectrophotometry matters for perovskite studies

1. It reveals micro scale variations that bulk measurements overlook

Perovskite research often focuses on how local structure shapes optical and electronic behavior. Grain interiors, grain boundaries, and small defect clusters may exhibit different bandgaps, emission strengths, or recombination pathways. As bulk spectroscopy averages these differences, interpretation becomes challenging. In contrast, microspectrophotometry examines microscale regions directly, providing optical signatures that reveal the origins of performance variations and support more targeted materials optimization.

Raman microspectroscopy provides complementary microscale information by probing crystal structure, phase composition, lattice disorder, and strain within the same localized regions. When applied to perovskite materials, Raman analysis helps distinguish structural and local compositional variations that underlie changes in optical response. Used alongside microspectrophotometry, Raman microspectroscopy strengthens structure-property correlations and improves understanding of how microscale heterogeneity influences perovskite performance.

2. It improves studies of film formation and uniformity

Precise control is required during perovskite film formation because even minor variations in thickness and crystallization can reshape the material's optical behavior. Microspectrophotometry can determine thickness through interference features within reflectance or transmission spectra. Since the method is non destructive and spatially resolved, it reveals gradients, incomplete coverage, or local defects that influence study outcomes. This information supports perovskite research by helping refine deposition techniques, tune annealing conditions, and improve solvent selection.

3. It strengthens degradation and environmental studies

Perovskites are highly sensitive to moisture, temperature, oxygen, and light, making stability a central concern in their development. Understanding how such materials evolve requires tools capable of monitoring subtle, time-dependent changes, like microspectrophotometry. With its high spatial and spectral sensitivity, microspectrophotometry reveals the earliest signs of degradation, from small changes in absorption to declining photoluminescence and the formation of darkened domains. These microscopic signals often precede measurable performance losses, ensuring researchers can see how and where the degradation begins. The early-stage information microspectrophotometry provides allows researchers to evaluate protective strategies, compare material formulations, and pinpoint the mechanisms that ultimately limit device stability.

How to conduct perovskite studies with a microspectrophotometer

1. Define the study objective and select the measurement mode

The research objective defines which optical measurement mode is required:

• Absorbance or transmission- determines bandgap, thickness, and compositional uniformity by quantifying the material's absorption and transmission of incident light.
• Reflectance- suited to opaque or multilayer perovskite films where transmitted light cannot be collected reliably, enabling assessment of surface and interface optical behavior.
• Photoluminescence (PL)- examines the material's emission characteristics, providing insight into recombination pathways, defect activity, and phase purity.

Selecting the correct mode ensures the resulting spectra align with the goals of the study and provide interpretable, relevant insight.

2. Prepare the sample and confirm substrate suitability

Sample preparation is critical for obtaining accurate microspectrophotometry data. Transmission measurements require transparent substrates, whereas reflectance measurements depend on reflective or opaque ones. The surface must be clean and uniform, as microscopic contaminants can distort local measurements. When analyzing individual crystals, make sure the mounting will hold them securely and keep them well resolved to ensure high-quality, spatially precise measurements.

3. Perform calibration with dark and reference scans

Calibration ensures microspectrophotometry measurements stay reliable. A dark scan removes detector background signals, while a reference scan accounts for illumination and optical system characteristics. For long acquisitions or environmental studies, recalibration may be needed to maintain consistent and comparable spectra.

4. Identify regions of interest and record microscale spectra

Perovskite studies often focus on specific regions of the film like grain centres, grain boundaries, areas with uneven thickness, or visible defects. A small measurement spot allows the microspectrophotometer to target these regions precisely. Gathering multiple spectra helps build a more robust and reliable interpretation of the sample's optical behavior.

5. Build spatial maps of optical behavior

By scanning across the sample in a raster or grid pattern, researchers can use microspectrophotometry to produce maps that show variations in photoluminescence intensity, bandgap, reflectance features, or optical density. These maps reveal spatial trends and help link local behaviour to overall sample performance.

6. Analyze spectral data according to the study goal

• Thickness studies- use interference patterns within the spectra to extract layer thickness and identify variations across the film.
• Degradation studies- monitor shifts in wavelength, changes in intensity, or the emergence of new spectral features to track how the material evolves over time.
• Structure-property investigations- compare spatial variations in emission or absorption to understand how microstructure influences optical behavior.

Microspectrophotometers utilize such analyses in perovskite studies to turn spectra features into insight, enriching researchers' interpretation of how the material behaves across the film.

Advancing Perovskite Research with Microspectrophotometry

Perovskite studies gain clarity from microspectrophotometry, which exposes local variations that would otherwise remain hidden. The technique's ability to resolve differences in structure, composition, and optical behavior across the film enables a more reliable interpretation of experimental results and deeper understanding of how these materials function. At CRAIC Technologies, we design microspectrophotometers that deliver the precision, resolution, and flexibility required for advanced perovskite studies. Our instruments support researchers as they continue to investigate these complex materials and develop the next generation of optoelectronic devices. Visit our website to learn more about our microspectrophotometers.

References

1. CRAIC Technologies. Perovskite Analysis: The Role of UV-Visible-NIR Microspectroscopy in Optoelectronic Research. AZoM. https://www.azom.com/article.aspx?ArticleID=23686. Published 11th June 2024. Accessed 1st December 2025.
2. CRAIC Technologies. An Overview of How Microspectrophotometers Work. AZoNano. https://www.azonano.com/article.aspx?ArticleID=2376. Published 11th September 2009. Accessed 1st December 2025.