LED Light Source Selection Guide for Solar Spectrum Simulators

Core Selection Principle: There is no universally optimal solution. The choice must fully match the device class (AAA/A/B), irradiation area, working distance, optical architecture, spectral range, and long‑term operating requirements. This document provides precise selection conclusions for key requirements: spectral matching, irradiation uniformity, long‑term stability, and light efficiency.
 
1. Core Package Selection: Ceramic 3535 (Single/Dual Chip) vs 5050 (Single/Quad Chip)

Solar simulators impose strict requirements on LEDs:
low thermal resistance, high power density, high wavelength/flux consistency, no spectral shift under long‑term operation.
Ceramic packaging is the only reliable solution (plastic PLCC packages cannot meet UV resistance and thermal stability).
Key Parameter Comparison

Specification	Typical Power	Thermal Resistance	Emitting Area	Key Advantages	Key Limitations
3535 Ceramic Single‑chip	1–3W	3–8℃/W	0.8–1.2mm	Small emitting area, high optical accuracy, no ghosting, high array density	Low maximum power; higher current density
3535 Ceramic Dual‑chip	3–6W	5–10℃/W	1.0–1.5mm	High power in small size; stable junction temperature	Lower thermal limit vs 5050
5050 Ceramic Single‑chip	3–5W	2–5℃/W	1.2–1.8mm	Large heat area, ultra‑low thermal resistance	Lower power vs quad‑chip
5050 Ceramic Quad‑chip	5–10W	3–6℃/W	2.0–2.5mm	Highest power density, low degradation, long lifetime	Slight ghosting in narrow collimated optics

Selection Recommendations
AAA‑Class Steady‑State Solar Simulators (PV IV Testing, IEC 60904‑9 / ASTM E927)
Recommended: 5050 Ceramic Quad‑chip (VIS–NIR) + 3535 Ceramic Dual‑chip (UV 300–400nm)

• Excellent thermal stability controls junction temperature variation within ±5℃
• Eliminates wavelength shift and lumen decay
• Fewer LEDs required to reach 1000W/㎡ irradiance
Compact / Portable / Small‑Area Systems (≤100cm²)
Recommended: 3535 Ceramic Single/Dual‑chip

• High array density, compact structure
• Good uniformity without complex homogenizers
Single‑chip vs Multi‑chip
• Single‑chip: For ultra‑narrow collimation and high‑precision imaging
• Multi‑chip (Dual/Quad): For >90% steady‑state applications; better thermal performance, longer lifetime
 
2. Lens Selection: Silicone Lens vs Fused Silica (Quartz) Lens
Core Conclusions
• Full spectrum (300–1200nm) & AAA‑class: MUST use fused silica lens
• 380–1100nm only & cost‑sensitive: High UV‑resistant silicone lens

Comparison

Item	Fused Silica Lens	High UV‑resistant Silicone Lens
UV Resistance	Stable 200–2500nm; no yellowing	Degrades rapidly <350nm
Transmittance	≥95% full spectrum	Drops sharply in deep UV
Thermal Stability	High heat resistance; no deformation	Deforms at high temperature
Lifetime	Matches chip lifetime	1–2 years under strong UV
Cost	High	Low

Critical Notes
• Deep UV (300–380nm) requires fused silica; silicone will yellow and fail spectrum compliance.
 
3. Beam Angle Selection: 60° vs 120°
Core Conclusions
• Large area (>200cm²), long distance (>200mm), AAA‑class: 60°
• Small area (≤200cm²), short distance (≤100mm), portable: 120°
60° Narrow Angle
• High intensity at long distance
• Excellent uniformity with flyeye / integrator (±2%)
• High light efficiency (>80%)
• Ideal for standard PV test systems (200×200mm, 300–500mm working distance)
120° Wide Angle
• Large coverage at short distance
• Good uniformity without complex optics (±5%)
• Lower component count and cost
• Suitable for benchtop and portable devices
 
4. Recommended Combinations for Customer Promotion

Device Type / Class	LED Package	Lens	Angle	Core Value
AAA Large‑Area PV Simulator	5050 Quad + 3535 Dual	Fused Silica	60°	Full A‑class spectrum, ultra‑stable
AAA High‑Precision Benchtop	3535 Dual	Fused Silica	60°	High optical accuracy
Economy / Portable	3535 Single/Dual	UV Silica/Quartz	120°	Cost‑effective, compact
Direct Array Light Source	5050 Single/Quad	UV Silicone	120°	High uniformity, easy assembly

 
5. Key Selection Tips
1. UV band (300–400nm): ceramic + fused silica only
2. Strict binning required: wavelength ±2nm, flux ±5%, voltage ±0.1V
3. Long‑term junction temperature ≤85℃ to avoid spectral shift and decay

Guangdong Juhong Optoelectronics Co., Ltd. specializes in manufacturing leds of various wavelengths and packaging types. Welcome to inquire