LEP Application

LEP Light Source: An Innovative Solution for Solar Simulators

Full spectrum+50000 hours lifespan, performance surpassing xenon lamp/LED

Preface

With the global in-depth research on renewable energy, materials science, and biotechnology, solar simulators have become increasingly critical as core experimental equipment. Their applications have expanded from basic photovoltaic material testing to high-precision fields such as photocatalysis, photodegradation, and photobiological experiments. This evolution demands higher requirements for light source performance, including spectral matching, irradiation stability, and uniformity. Current mainstream light sources like xenon lamps and LEDs struggle to meet these specialized needs due to technical limitations. In contrast, Light Emitting Plasma (LEP) technology, with its superior spectral characteristics and technical advantages, is emerging as a revolutionary solution for solar simulators. This article systematically elaborates on the core advantages of LEP over xenon lamps and LEDs across key dimensions: spectral properties, color rendering, stability, lumen maintenance, and power efficiency.

I. Spectral Characteristics: Continuous Full Spectrum Closest to Sunlight

Sunlight spans a continuous spectrum covering ultraviolet (UV, 290–400 nm), visible (VIS, 400–700 nm), and infrared (IR, 700–2500 nm) bands. Traditional light sources fall short in spectral fidelity:

1. Xenon Lamps: Although offering a broad range (200–2000 nm), they exhibit insufficient UV intensity, excessive IR emission, and spectral discontinuity due to unstable arc discharge.

2. LEDs: Limited by semiconductor physics, LEDs rely on multi-chip matrixes to approximate a broad spectrum, resulting in discontinuous spectral peaks, excessive blue light spikes, and missing UV/IR bands.

3. LEP: Utilizing microwave-excited plasma, LEP delivers a continuous spectrum from 290–1800 nm without spikes or gaps. Its UV (290–400 nm) and near-IR (700–1800 nm) intensities closely match sunlight. Experimental data confirm that LEP’s red, green, and blue light ratios in the visible range deviate from sunlight by less than 3%, achieving Class A compliance under the IEC 60904-9 standard.

Technical Value:

For applications requiring specific bands (e.g., UV-dependent photocatalysis or red/blue-light-driven plant growth), LEP’s full-spectrum output eliminates the need for supplemental filters or additional light sources. This simplifies optical design and reduces experimental errors. For perovskite and perovskite-silicon tandem solar cell testing, LEP’s 290–1800 nm range fully covers the spectral response of silicon-based cells (300–1200 nm) and perovskite cells (extended to 1800 nm), avoiding test deviations caused by traditional light sources’ band limitations.

II. Color Rendering: Ra97 High CRI and Stable Correlated Color Temperature

The Color Rendering Index (CRI, Ra) measures a light source’s ability to reveal object colors accurately, with sunlight defining Ra100. Traditional light sources face significant shortcomings:

• Xenon Lamps: Ra 90–94, but color temperature fluctuates with power instability and lamp aging, requiring frequent recalibration.

• LEDs: Multi-spectral LEDs typically achieve Ra <90, with inconsistent color temperatures and spectral shifts due to chip degradation over time.

• LEP: Achieves Ra97, nearing natural sunlight’s color fidelity. Its stable correlated color temperature (5500–6000K, matching AM1.5G sunlight) remains unaffected by environmental temperature or operational duration.

Application Advantages:

In photobiological studies (e.g., plant cultivation) or material weathering tests, high CRI ensures objective results by preventing data distortion from color bias. For instance, excessive blue light from LEDs can inhibit plant growth, while LEP’s balanced spectrum accurately replicates natural conditions.

III. Irradiation Stability and Uniformity: AAA-Class Performance

The ASTM E927 standard classifies solar simulators into Grades A (highest) to C based on irradiation uniformity, stability, and spectral match. LEP achieves AAA-grade performance:

1. Irradiation Stability:

• Xenon lamps suffer ±2% instability due to arc flicker and power fluctuations.

• LEDs require complex thermal management to mitigate lumen decay, compromising long-term stability.

• LEP employs solid-state microwave excitation (440 MHz, far exceeding the 3125 Hz flicker-free threshold) with no electrode degradation, achieving <±1% stability.

2. Irradiation Uniformity:

With a compact 0.4 cm³ plasma volume (near-point-source geometry), LEP achieves >98% uniformity via secondary optics (e.g., integrators or lens matrixes). Xenon lamps, constrained by elongated arc structures, face inherent uniformity challenges.

Case Study:

In photovoltaic module testing, xenon lamp-induced hotspots can cause up to 5% efficiency measurement errors, while LEP’s uniformity reduces errors to <1%.

IV. Lumen Maintenance and Lifespan: 50,000-Hour Ultra-Longevity

Light source decay directly impacts maintenance costs and experimental consistency:

• Xenon Lamps: 1,000–2,000-hour lifespan, with rapid decay (60% lumen output after 2,000 hours).

• LEDs: Rated 50,000 hours, but blue chip degradation under high temperatures reduces real-world lumen maintenance to <70%.

• LEP: Electrode-free microwave excitation ensures minimal physical wear. After 50,000 hours of continuous operation, LEP retains >80% initial output, offering 25× longer service life than xenon lamps.

Economic Benefits:

Operating 24/7, LEP lasts nearly 6 years, reducing annual maintenance costs by over 90% compared to xenon lamps—ideal for industrial testing requiring uninterrupted operation.

V. Power Density and Efficiency: High-Fidelity AM1.5G Compliance

LEP delivers a power density of 1000 W/m² (1.0 Sun), meeting AM1.5G standards with >70% energy conversion efficiency—far surpassing xenon lamps (15%) and LEDs (25%). Key advantages include:

1. High Luminance: A single LEP bulb emits 23,000 lumens, offering 10× higher volumetric intensity than xenon lamps.

2. Ultra-Low Power Consumption: Stable operation requires only 260W, saving 40% energy versus xenon lamps.

3. Low Thermal Load: LEP operates at a temperature rise <35°C (@25°C ambient), whereas LEDs require active cooling (often exceeding 80°C), preventing sample thermal interference.

VI. Total Cost of Ownership and Future Potential

Despite higher initial costs, LEP’s lifecycle advantages are transformative:

• Maintenance Costs: Eliminate electrode/lamp replacements and reduce energy use by >40%.

• System Costs: Simplify power supplies (vs. xenon’s high-voltage modules) and driver circuits (vs. multi-channel LED systems).

• Scalability: Modular LEP matrixes enable kilowatt-level irradiation for aerospace-grade testing.

Conclusion

In the evolving landscape of solar simulation, LEP is redefining industry standards with its full-spectrum coverage, ultra-stability, longevity, and low maintenance. For manufacturers, adopting LEP enhances product competitiveness while meeting the precision demands of photochemistry, photobiology, and next-gen solar cell testing. As LEP manufacturing processes advance, cost reductions and performance upgrades will drive solar simulators toward greater efficiency and intelligence. Choosing LEP means embracing the benchmark of next-generation solar simulation technology.

Video: Plasma light source(LEP) leads technological innovation in solar simulators