Photoelectric Conversion Efficiency (IPCE, Incident Photon-to-Current Efficiency) is a key characterization parameter in photoelectrocatalysis and photovoltaic research. It evaluates a material's ability to convert incident photons into photocurrent under light of different wavelengths, reflecting the material's photoelectric conversion efficiency and wavelength dependence.
Pan et al., Nature Communications, 2020. https://doi.org/10.1038/s41467-019-13987-5
The measurement of IPCE imposes stringent requirements on the light source, as its performance directly impacts the accuracy and repeatability of experimental results. Studies have shown that factors such as spectral range, light intensity stability, and spot uniformity are critical to IPCE measurement accuracy[1,2]. This article analyzes the key requirements and selection criteria for light sources in IPCE measurements.
IPCE measurements require the light source to cover the material's light absorption range to meet the testing needs of various materials. For example:
• Wide-bandgap materials (e.g., TiO₂) primarily absorb ultraviolet light, requiring light sources to provide UV light with wavelengths shorter than 400 nm.
• Narrow-bandgap materials (e.g., g-C₃N₄, BiVO₄) are sensitive to visible light and require light sources covering the 400–700 nm visible light range.
• Near-infrared-responsive materials need light sources with spectral ranges extending beyond 700 nm.
Due to its ability to cover UV, visible, and some near-infrared regions, xenon lamps are a common choice for IPCE measurements because of their wide spectral range[3].
Porphyrin Technology PLS-FX300HU High-Uniformity Integrated Xenon Lamp is a dedicated xenon lamp for photoelectrocatalysis research. Its spectral range of 320–800 nm covers UV and visible light regions, meeting the IPCE measurement needs of both wide-bandgap and narrow-bandgap materials. Additionally, this light source supports the use of UV, visible, and narrow-bandpass filters for flexible monochromatic light output.
Light intensity stability is a critical factor for IPCE measurements, as fluctuations in light intensity directly affect photocurrent density measurements, significantly impacting the accuracy and repeatability of experimental data[4]. Generally, light intensity fluctuations should be less than 1% to ensure measurement reliability and repeatability.
PLS-FX300HU High-Uniformity Integrated Xenon Lamp features a precision optical feedback system that monitors and adjusts light output in real-time, ensuring highly stable light intensity. Its short-term stability meets A+ standards, with 1-second fluctuations of only 0.04% and 1-minute fluctuations of only 0.003%, fully meeting the stringent requirements of IPCE measurements.
IPCE measurements require the light source to provide a uniform light spot to ensure consistent illumination on the sample surface and avoid measurement errors caused by uneven light intensity distribution.
PLS-FX300HU High-Uniformity Integrated Xenon Lamp outputs a rectangular uniform light spot with ±1% non-uniformity. The spot size is continuously adjustable from 10×10 mm² to 50×50 mm², flexibly adapting to photoelectrode testing requirements of different sizes. When the spot size is ≤20×20 mm², its uniformity reaches the A-level solar simulator standard, ensuring highly uniform illumination on the sample surface.
IPCE measurements require monochromatic light, which can be achieved through:
• A broadband light source (e.g., xenon lamp) combined with a monochromator.
• Specific wavelength LED light sources or laser light sources.
PLS-FX300HU High-Uniformity Integrated Xenon Lamp can be paired with Porphyrin bandpass filters for flexible monochromatic light output, meeting the needs of IPCE measurements.
IPCE measurements require precise knowledge of the incident light power density at each wavelength, so the light source must be calibrated. Calibration should consider all losses in the optical path, including the transmittance of monochromators and filters[5].
PLS-FX300HU High-Uniformity Integrated Xenon Lamp supports current regulation and motorized diaphragms for fine light intensity control, facilitating calibration and optimization of experimental conditions.
IPCE measurements impose stringent requirements on light sources. Suitable light sources must offer a wide spectral range, high light intensity stability, uniform light spots, and flexible monochromatic light output capabilities. The PLS-FX300HU High-Uniformity Integrated Xenon Lamp, with its exceptional performance, meets these requirements, making it the dedicated xenon lamp for photoelectrocatalysis research.
By selecting and using appropriate light sources, the accuracy and repeatability of IPCE measurements can be significantly improved, providing reliable data support for photoelectric material performance research.
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▷References
[1] A. Fujishima, K. Honda, "Electrochemical Photolysis of Water at a Semiconductor Electrode," Nature, 1972.
[2] M. Grätzel, "Photoelectrochemical Cells," Nature, 2001.
[3] J. Bisquert, "Theory of the Impedance of Electron Diffusion and Recombination in a Thin Layer," Journal of Physical Chemistry B, 2002.
[4] H. Tributsch, "Reaction of Excited Chlorophyll Molecules at Electrodes and in Photosynthesis," Photochemistry and Photobiology, 1972.
[5] A. Hagfeldt, "Photoelectrochemical and Photovoltaic Properties of Dye-Sensitized Solar Cells," Accounts of Chemical Research, 2000.
