Electrolyte photo-induced luminescence testing service

Electrolyte Photo‑Induced Luminescence Testing Service – Accredited Photochemical and Material Integrity Assessment for Optoelectronic and Energy Devices

For Bangladeshi renewable energy developers, electronics manufacturers, research institutions, and quality assurance teams, the interaction between light and electrolyte‑containing materials – in solar cells, batteries, sensors, and display devices – fundamentally determines device efficiency, stability, and long‑term reliability. Our ISO/IEC 17025 accredited laboratory offers a comprehensive electrolyte photo‑induced luminescence testing service that combines controlled photo‑excitation with high‑resolution luminescence detection to assess charge carrier dynamics, defect states, ion migration, and degradation mechanisms in real‑time. With decades of experience in photoelectrochemistry and materials characterisation, we help you qualify novel electrolytes, optimise device architectures, verify imported components, and meet the evolving technical requirements of the Bangladesh Standards and Testing Institution (BSTI), the Sustainable and Renewable Energy Development Authority (SREDA), and international certification bodies for photovoltaic and optoelectronic products.

Product Samples We Regularly Test

We accept a broad range of solid, liquid, and gel‑based electrolyte systems and assembled devices where photo‑induced luminescence provides critical performance insights. Our test configurations accommodate cells, films, and complete device stacks. Common samples include:

• Dye‑sensitised solar cells (DSSCs) and perovskite solar cells – complete photovoltaic devices with electrolyte layers.
• Lithium‑ion and sodium‑ion battery electrodes with liquid electrolytes – for in‑situ luminescence during charging/discharging.
• Electrochromic and smart glass devices – ion‑conducting layers with photo‑response.
• Photoelectrochemical (PEC) water‑splitting cells – semiconductor/electrolyte interfaces.
• Light‑emitting electrochemical cells (LECs) and quantum‑dot LEDs – electrolyte‑containing emissive layers.
• Sensor materials and ion‑selective membranes – with photo‑active indicator dyes.
• Solid‑state electrolytes and gel polymers – for next‑generation batteries and supercapacitors.
• Photocatalytic and self‑cleaning coatings – containing photo‑active electrolytes.

Steady‑State Photoluminescence (PL) and Electrolyte Interaction

Steady‑state PL is the foundational technique in our electrolyte photo‑induced luminescence testing service, revealing the efficiency of radiative recombination and the influence of the electrolyte on emission intensity:

• PL emission spectrum under controlled illumination (ASTM E2719, ISO 20720, custom) – We excite the sample with a monochromatic light source (e.g., 405 nm, 532 nm, or solar‑simulated) and record the resulting luminescence spectrum from 350 nm to 1100 nm. The spectral shape, peak wavelength, and full‑width‑half‑maximum (FWHM) indicate the electronic structure and the presence of defect states. By comparing measurements with and without electrolyte contact, we quantify the quenching or enhancement of luminescence due to charge transfer or ion‑induced passivation.
• PL intensity mapping and imaging (ISO 18380, ASTM E2912) – We scan the sample area using a motorised stage and a focused laser, creating a 2D PL intensity map that reveals spatial non‑uniformities – such as phase segregation, electrolyte penetration inhomogeneity, or electrode contamination – which are critical for quality control and failure diagnostics.
• Temperature‑dependent PL (4 K to 400 K – ASTM E2070, custom cryostat) – We measure the luminescence spectrum at multiple temperatures to identify exciton binding energy, activation energy of non‑radiative centres, and phase transitions in the electrolyte‑material interface – crucial for understanding thermal stability in real‑world applications.
• PL quantum efficiency and external quantum efficiency (EQE) correlation (ISO 18380, ASTM E1021) – We integrate the PL spectrum over wavelength and compare it with a calibrated reference to determine the photoluminescence quantum yield (PLQY). We then correlate PLQY with the device’s external quantum efficiency (EQE) to estimate the internal quantum efficiency, a key indicator of charge carrier utilisation.
• Ambient vs. inert atmosphere PL (glove‑box and sealed cell measurements) – For air‑sensitive electrolytes (e.g., LiPF₆ in organic solvents), we perform measurements under nitrogen or argon to separate the intrinsic luminescence from oxygen‑ or moisture‑induced quenching, providing a baseline for degradation analysis.

Time‑Resolved Photoluminescence (TRPL) and Charge Carrier Dynamics

TRPL measures the luminescence decay kinetics after a short laser pulse, revealing charge carrier lifetimes and recombination pathways that are strongly modulated by the electrolyte:

• TRPL lifetime measurement (ISO 24044, ASTM E3025, custom time‑correlated single photon counting – TCSPC) – We excite the sample with a picosecond or nanosecond pulsed laser and record the decay of PL intensity over time. We fit the decay curve with single‑ or multi‑exponential functions to extract the lifetime components (τ₁, τ₂, …). The average lifetime and the weighted contributions of fast and slow components indicate the effectiveness of charge extraction and the presence of trap‑assisted recombination – both of which are influenced by electrolyte composition and ion motion.
• TRPL at different laser fluences and bias voltages (ASTM E3025, custom) – By varying the excitation power, we assess the dependence of lifetime on carrier density, identifying Auger recombination or saturation of defect states. We can also apply an external bias across the sample during TRPL to simulate operating conditions and detect voltage‑dependent ion migration that causes luminescence quenching or transient enhancement.
• Mono‑exponential vs. distributed lifetime analysis – using intensity‑decay and phasor plots – For complex systems with multiple emitter populations (e.g., mixed halide perovskites), we use advanced analysis tools to deconvolve the lifetime distribution, providing a more accurate picture of the heterogeneity induced by electrolyte‑material interactions.
• TRPL at controlled temperature and electric field (custom cryostat with bias contacts) – We combine temperature control (down to 4 K) with in‑situ electrical biasing while recording TRPL, allowing us to study the activation energy of non‑radiative pathways and the field‑assisted dissociation of excitons – essential for understanding the stability of electrolyte‑containing devices under operation.
• Surface and bulk lifetime separation – using variable excitation depth – By using different excitation wavelengths (e.g., 405 nm for surface, 785 nm for bulk), we differentiate the luminescence decay of the near‑surface region (which is directly affected by the electrolyte) from the bulk, providing insight into interface recombination kinetics.

Electrolyte‑Induced Degradation and Ion Migration Monitoring

One of the most critical applications of photo‑induced luminescence is tracking the real‑time degradation of electrolytes and their interfaces. Our service includes accelerated photo‑aging with in‑situ PL monitoring:

• Photo‑aging with simultaneous PL tracking (ASTM E2694, IEC 61215, custom) – We expose the sample to continuous solar‑simulated light (AM 1.5G, 1‑10 suns) while periodically measuring PL spectra and intensity. The decrease in PL intensity over time correlates with electrolyte decomposition, ion migration, or electrode corrosion. We report the half‑life of PL intensity (T₅₀) as an indicator of the electrolyte’s photostability.
• Ion migration tracked by PL quenching/rebrightening (custom bias‑dependent PL) – We apply a DC bias across the sample and observe the PL response over time. A gradual decrease in PL under bias indicates ion accumulation at interfaces (e.g., Li⁺ migration in perovskite), while a recovery after bias removal suggests reversible ion redistribution. This is critical for understanding hysteresis and stability in perovskite solar cells and batteries.
• Electrochemical PL under potentiostatic or galvanostatic control (custom photoelectrochemical setup) – We connect the sample to a potentiostat and sweep the electrode potential while recording PL spectra. The change in PL as a function of potential reveals the redox state of the electrolyte, the charge transfer kinetics, and the onset of degradation reactions – providing a direct correlation between electrochemical and optical behaviour.
• Fluorescence microscopy for localised degradation (ASTM E2794, ISO 16790) – Using a fluorescence microscope, we examine the sample surface after photo‑aging to identify luminescence hot‑spots (indicative of phase aggregation) or dark regions (indicating localised electrolyte decomposition). We provide high‑resolution images with quantitative intensity analysis.
• Mass spectrometry (GC‑MS or LC‑MS) of electrolyte before and after photo‑exposure – We extract the electrolyte from the aged sample and analyse its chemical composition to detect degradation by‑products (e.g., HF, PF₅, or organic fragments), correlating the chemical changes with the luminescence decline observed in‑situ.

Wavelength‑Dependent and Selective Excitation Luminescence

Different excitation wavelengths probe different depths and electronic states. Our systems offer variable excitation from UV to NIR to build a comprehensive photophysical picture:

• Photoluminescence excitation (PLE) spectroscopy (ASTM E2719, ISO 20720) – We scan the excitation wavelength (typically 300‑800 nm) while monitoring the luminescence at a fixed emission wavelength. The resulting PLE spectrum reveals which absorption bands contribute to the luminescence, helping to identify the active species in the electrolyte and the semiconductor.
• Selective excitation of bulk vs. interface (using 405 nm, 532 nm, and 785 nm lasers) – By comparing PL spectra obtained with different laser wavelengths (which have different penetration depths), we can separate the luminescence originating from the bulk semiconductor from that of the electrolyte‑semiconductor interface, providing independent assessments of each region.
• Up‑conversion luminescence (UCL) for deep penetration and anti‑Stokes analysis – For samples with thick electrolyte layers or opaque electrodes, we use near‑infrared excitation (e.g., 980 nm) to generate up‑converted visible luminescence, which enables us to probe buried interfaces without destructive sectioning.
• Spectrally resolved PL under varying bias and intensity – emission peak shifts as electrochemical indicators – We monitor the shift of the PL peak wavelength under different external conditions. A red‑shift may indicate bandgap narrowing due to Joule heating or doping, while a blue‑shift may suggest phase segregation – both of which are influenced by the ionic composition of the electrolyte.
• Polarisation‑resolved PL for anisotropic materials (ASTM E2535, custom) – For aligned polymers or anisotropic semiconductor crystals, we measure the luminescence intensity as a function of polarisation angle, providing structural information about the electrolyte‑material interface and any orientation‑dependent charge transfer.

Device‑Level and Module‑Scale Luminescence Testing

We extend our service from coupon‑level to full mini‑modules and encapsulated devices, mimicking real product configurations:

• Electroluminescence (EL) and photoluminescence (PL) correlation on complete devices (IEC 60904‑12, ASTM E2524) – We perform both EL (by forward biasing the device) and PL (by optical excitation) on the same solar cell, battery, or LEC. The comparison reveals whether the luminescence arises from similar recombination pathways or if electrical injection introduces additional losses (e.g., series resistance, contact effects) that are not seen in photo‑excitation.
• Large‑area PL imaging (up to 600 mm × 600 mm) for monolithic modules (ISO 18380, ASTM E2912) – Using a large‑area scanning system, we map the luminescence uniformity across entire modules, detecting edge delamination, electrolyte leakage, and non‑uniform degradation – invaluable for factory quality control and field failure analysis.
• In‑situ PL during accelerated environmental testing (temperature/humidity + light exposure – IEC 61215, IEC 61730) – We place the device in an environmental chamber and perform PL measurements at intervals while the chamber cycles between 25°C/50%RH and 85°C/85%RH under continuous illumination. This simulates monsoon and heat conditions and identifies humidity‑induced electrolyte decomposition before it becomes visible as physical damage.
• Electrolyte thickness and composition variation – PL response to formulation changes – For developers, we test a series of electrolyte formulations (different redox couples, additives, or solvents) under identical illumination and report the PL intensity, lifetime, and spectral shape, helping you select the formulation that maximises charge carrier longevity and minimises photo‑degradation.
• PL during dynamic electrochemical impedance spectroscopy (EIS) – combined optical‑electrical characterisation – We simultaneously measure PL and EIS (over frequency from 1 mHz to 1 MHz) while applying a DC bias, allowing us to correlate ionic conductivity, charge transfer resistance, and photoluminescence in a single experiment – a powerful diagnostic for electrolyte optimisation.

Data Analysis and Reporting – From Spectra to Actionable Insights

Our service provides not only raw spectra but also comprehensive quantitative parameters that guide material and device development:

• PL peak fitting and deconvolution (Lorentzian, Gaussian, or Voigt profiles – ASTM E2524) – We fit the recorded PL spectra to resolve overlapping emission peaks, each representing a different electronic transition or emissive species. The relative intensities, peak positions, and widths are tabulated and compared across test conditions.
• Lifetime distribution analysis – using maximum entropy and stretched‑exponential fitting (KWW model) – For complex decay curves, we apply advanced fitting algorithms to extract a distribution of lifetimes, providing a more realistic description of charge carrier dynamics in heterogeneous electrolyte‑containing systems.
• Degradation rate calculation (PL intensity vs. time, with exponential or polynomial fitting) – We fit the time‑dependent PL intensity data to a model (e.g., single‑exponential decay, double‑exponential, or linear) and report the degradation constant (k) and the predicted lifetime to 50% and 20% of initial PL intensity.
• Statistical comparisons – mean, standard deviation, and confidence intervals for multiple samples – For batch‑to‑batch qualification, we test multiple replicates and provide a statistical summary that includes the coefficient of variation, enabling you to establish control limits for production.
• Correlation with device performance parameters – efficiency, fill factor, open‑circuit voltage – Where possible, we measure the device’s I‑V characteristics and EQE alongside PL, and we provide a correlation matrix that shows which PL parameters (intensity, lifetime, peak shift) are most predictive of device performance – a valuable tool for in‑line quality control.

Report Accreditation and Compliance for Bangladesh

All photo‑induced luminescence test methods described above are performed within our ISO/IEC 17025:2017 accredited quality system, ensuring traceable calibration of spectrometers, lasers, power meters, and temperature sensors, as well as validated measurement procedures and certified technical staff. Our test reports are recognised by the Bangladesh Standards and Testing Institution (BSTI) for product certification and import clearance, and they satisfy the technical documentation requirements of the Sustainable and Renewable Energy Development Authority (SREDA) for solar and battery energy storage systems, as well as the Bangladesh Energy Regulatory Commission (BERC) for efficiency and safety assessments. For export‑oriented electronics and photovoltaic manufacturers, our reports align with international standards (IEC, ISO, ASTM, JIS) frequently demanded by buyers in the EU, USA, Japan, and Southeast Asia. Each report includes a complete description of the test setup (excitation wavelength, power density, environmental conditions), raw and processed spectra, decay curves, fitted parameters (intensity, lifetime, peak position), imaging results, degradation analysis, and a professional interpretation of the electrolyte’s photo‑stability and material integrity – giving you the confidence to optimise your formulations, qualify suppliers, and certify products for local and international markets.

Why Choose Our Electrolyte Photo‑Induced Luminescence Testing Service

We understand that the interplay between light and electrolyte materials is complex and often the limiting factor for device lifetime. Our team combines expertise in photophysics, electrochemistry, and materials science to provide insightful analysis that goes beyond standard test reports – we explain the physical meaning of your PL data and suggest targeted strategies to improve stability, reduce ion migration, or enhance charge extraction. We work flexibly with your R&D, production, or procurement teams to design test plans that match your specific needs, whether it is rapid screening of new electrolyte formulations, in‑depth failure analysis of field‑returned products, or routine batch‑release testing. With state‑of‑the‑art instrumentation and rigorous quality practices, our electrolyte photo‑induced luminescence testing service delivers the precision, reproducibility, and technical depth that advanced energy and optoelectronic applications demand. Contact us to discuss your sample types, target performance indicators, and operating conditions – we will create a customised testing programme that sheds light on your electrolyte’s true photochemical behaviour and helps you build more durable and efficient devices.